From bd862d351789a2859a083ac9f77364be25dbadc5 Mon Sep 17 00:00:00 2001
From: Mateusz Pusz <mateusz.pusz@gmail.com>
Date: Wed, 7 Apr 2021 11:26:45 +0200
Subject: [PATCH] refactor: Fine-grained references support added

---
 docs/framework/quantities.rst                          | 10 ++++++++--
 example/references/box_example.cpp                     |  6 ++++--
 example/references/experimental_angle.cpp              |  8 ++++----
 example/references/linear_algebra.cpp                  |  4 ++--
 example/references/total_energy.cpp                    |  4 ++--
 src/core/include/units/generic/angle.h                 |  8 +++++++-
 src/core/include/units/reference.h                     |  8 +++++++-
 .../include/units/isq/iec80000/modulation_rate.h       |  8 +++++++-
 .../include/units/isq/iec80000/storage_capacity.h      |  8 +++++++-
 .../include/units/isq/iec80000/traffic_intensity.h     |  8 +++++++-
 .../si-cgs/include/units/isq/si/cgs/acceleration.h     |  8 +++++++-
 src/systems/si-cgs/include/units/isq/si/cgs/area.h     |  8 +++++++-
 src/systems/si-cgs/include/units/isq/si/cgs/energy.h   |  8 +++++++-
 src/systems/si-cgs/include/units/isq/si/cgs/force.h    |  8 +++++++-
 src/systems/si-cgs/include/units/isq/si/cgs/length.h   |  8 +++++++-
 src/systems/si-cgs/include/units/isq/si/cgs/mass.h     |  8 +++++++-
 src/systems/si-cgs/include/units/isq/si/cgs/pressure.h |  8 +++++++-
 src/systems/si-cgs/include/units/isq/si/cgs/time.h     |  8 +++++++-
 src/systems/si-fps/include/units/isq/si/fps/area.h     |  8 +++++++-
 src/systems/si-fps/include/units/isq/si/fps/force.h    |  8 +++++++-
 src/systems/si-fps/include/units/isq/si/fps/length.h   |  8 +++++++-
 src/systems/si-fps/include/units/isq/si/fps/mass.h     |  8 +++++++-
 src/systems/si-fps/include/units/isq/si/fps/power.h    |  8 +++++++-
 src/systems/si-fps/include/units/isq/si/fps/pressure.h |  8 +++++++-
 src/systems/si-fps/include/units/isq/si/fps/speed.h    |  8 +++++++-
 src/systems/si-fps/include/units/isq/si/fps/time.h     |  8 +++++++-
 src/systems/si-fps/include/units/isq/si/fps/volume.h   |  8 +++++++-
 src/systems/si-iau/include/units/isq/si/iau/length.h   |  8 +++++++-
 .../si-imperial/include/units/isq/si/imperial/length.h |  8 +++++++-
 .../include/units/isq/si/international/area.h          |  8 +++++++-
 .../include/units/isq/si/international/length.h        |  8 +++++++-
 .../include/units/isq/si/international/volume.h        |  8 +++++++-
 .../include/units/isq/si/typographic/length.h          |  8 +++++++-
 src/systems/si-us/include/units/isq/si/us/length.h     |  8 +++++++-
 src/systems/si/include/units/isq/si/absorbed_dose.h    |  8 +++++++-
 .../si/include/units/isq/si/amount_of_substance.h      |  8 +++++++-
 src/systems/si/include/units/isq/si/area.h             |  8 +++++++-
 src/systems/si/include/units/isq/si/capacitance.h      |  8 +++++++-
 .../si/include/units/isq/si/catalytic_activity.h       |  9 +++++++--
 src/systems/si/include/units/isq/si/conductance.h      |  8 +++++++-
 src/systems/si/include/units/isq/si/electric_charge.h  |  8 +++++++-
 src/systems/si/include/units/isq/si/electric_current.h |  8 +++++++-
 src/systems/si/include/units/isq/si/energy.h           |  9 ++++++++-
 src/systems/si/include/units/isq/si/force.h            |  8 +++++++-
 src/systems/si/include/units/isq/si/frequency.h        |  8 +++++++-
 src/systems/si/include/units/isq/si/inductance.h       |  8 +++++++-
 src/systems/si/include/units/isq/si/length.h           |  8 +++++++-
 .../si/include/units/isq/si/luminous_intensity.h       |  8 +++++++-
 src/systems/si/include/units/isq/si/magnetic_flux.h    |  8 +++++++-
 .../si/include/units/isq/si/magnetic_induction.h       |  8 +++++++-
 src/systems/si/include/units/isq/si/mass.h             |  8 +++++++-
 src/systems/si/include/units/isq/si/power.h            |  8 +++++++-
 src/systems/si/include/units/isq/si/pressure.h         |  8 +++++++-
 src/systems/si/include/units/isq/si/radioactivity.h    |  8 +++++++-
 src/systems/si/include/units/isq/si/resistance.h       |  8 +++++++-
 .../include/units/isq/si/thermodynamic_temperature.h   |  8 +++++++-
 src/systems/si/include/units/isq/si/time.h             | 10 ++++++++--
 src/systems/si/include/units/isq/si/voltage.h          |  8 +++++++-
 src/systems/si/include/units/isq/si/volume.h           |  8 +++++++-
 59 files changed, 400 insertions(+), 68 deletions(-)

diff --git a/docs/framework/quantities.rst b/docs/framework/quantities.rst
index b003bc94..cc6dea2f 100644
--- a/docs/framework/quantities.rst
+++ b/docs/framework/quantities.rst
@@ -58,12 +58,18 @@ They are defined using the `reference` class template::
 
     #ifdef UNITS_REFERENCES
 
-    namespace references {
+    namespace length_references {
 
     inline constexpr auto km = reference<dim_length, kilometre>{};
     inline constexpr auto h = reference<dim_time, hour>{};
 
-    }
+    }  // namespace length_references
+
+    namespace references {
+
+    using namespace length_references;
+
+    }  // namespace references
 
     #endif // UNITS_REFERENCES
 
diff --git a/example/references/box_example.cpp b/example/references/box_example.cpp
index 92743e3e..facf6d8f 100644
--- a/example/references/box_example.cpp
+++ b/example/references/box_example.cpp
@@ -39,12 +39,12 @@
 namespace {
 
 using namespace units::isq;
-using namespace si::references;
+using namespace si::mass_references;
+using namespace si::volume_references;
 
 inline constexpr Acceleration auto g = si::si2019::standard_gravity<>;
 inline constexpr Density auto air_density = 1.225 * (kg / m3);
 
-
 class Box {
   si::area<si::square_metre> base_;
   si::length<si::metre> height_;
@@ -82,6 +82,8 @@ public:
 int main()
 {
   using namespace units;
+  using namespace si::length_references;
+  using namespace si::time_references;
 
   const si::length<si::metre> height = 200.0 * mm;
   auto box = Box(1000.0 * mm, 500.0 * mm, height);
diff --git a/example/references/experimental_angle.cpp b/example/references/experimental_angle.cpp
index 4d04fbe6..2e2622a6 100644
--- a/example/references/experimental_angle.cpp
+++ b/example/references/experimental_angle.cpp
@@ -24,21 +24,21 @@
 
 UNITS_DIAGNOSTIC_PUSH
 UNITS_DIAGNOSTIC_IGNORE_SHADOW
+#include <units/isq/si/force.h>
+UNITS_DIAGNOSTIC_POP
+
 #include <units/generic/angle.h>
 #include <units/isq/si/energy.h>
-#include <units/isq/si/force.h>
 #include <units/isq/si/length.h>
 #include <units/isq/si/torque.h> // IWYU pragma: keep
 #include <units/quantity_io.h>
-UNITS_DIAGNOSTIC_POP
-
 #include <iostream>
 
 int main()
 {
-  using namespace units::references;
   using namespace units::isq;
   using namespace units::isq::si::references;
+  using namespace units::references;
 
   Torque auto torque = 20.0 * (N * m / rad);
   Energy auto energy = 20.0 * J;
diff --git a/example/references/linear_algebra.cpp b/example/references/linear_algebra.cpp
index 1dbd658c..94214542 100644
--- a/example/references/linear_algebra.cpp
+++ b/example/references/linear_algebra.cpp
@@ -60,7 +60,8 @@ std::ostream& operator<<(std::ostream& os, const matrix<ET, OT>& v)
 namespace {
 
 using namespace units::isq;
-using namespace units::isq::si::references;
+using namespace units::isq::si::length_references;
+using namespace units::isq::si::force_references;
 
 template<typename Rep = double>
 using vector = std::math::fs_vector<Rep, 3>;
@@ -68,7 +69,6 @@ using vector = std::math::fs_vector<Rep, 3>;
 template<typename Rep = double>
 using matrix = std::math::fs_matrix<Rep, 3, 3>;
 
-
 void vector_of_quantity_add()
 {
   std::cout << "\nvector_of_quantity_add:\n";
diff --git a/example/references/total_energy.cpp b/example/references/total_energy.cpp
index 0398c82f..71c72c9e 100644
--- a/example/references/total_energy.cpp
+++ b/example/references/total_energy.cpp
@@ -21,11 +21,11 @@
 // SOFTWARE.
 
 #include <units/isq/natural/natural.h>
+#include <units/isq/si/constants.h>
 #include <units/isq/si/energy.h>
 #include <units/isq/si/mass.h>
 #include <units/isq/si/momentum.h>
 #include <units/isq/si/speed.h> // IWYU pragma: keep
-#include <units/isq/si/constants.h>
 #include <units/math.h>
 #include <units/quantity_io.h>
 #include <exception>
@@ -43,7 +43,7 @@ Energy auto total_energy(Momentum auto p, Mass auto m, Speed auto c)
 void si_example()
 {
   using namespace units::isq::si;
-  using namespace units::isq::si::references;
+  using namespace units::isq::si::energy_references;
 
   constexpr Speed auto c = si2019::speed_of_light<>;
 
diff --git a/src/core/include/units/generic/angle.h b/src/core/include/units/generic/angle.h
index 26fdd80c..76bd1f51 100644
--- a/src/core/include/units/generic/angle.h
+++ b/src/core/include/units/generic/angle.h
@@ -57,10 +57,16 @@ constexpr auto operator"" _q_rad(long double l) { return angle<radian, long doub
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace angle_references {
 
 inline constexpr auto rad = reference<dim_angle<>, radian>{};
 
+}  // namespace angle_references
+
+namespace references {
+
+using namespace angle_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/core/include/units/reference.h b/src/core/include/units/reference.h
index 31e4f388..799d915d 100644
--- a/src/core/include/units/reference.h
+++ b/src/core/include/units/reference.h
@@ -61,12 +61,18 @@ using reference_divide = detail::reference_divide_impl<
  * This type is intended to be used in the quantity references definition:
  *
  * @code{.cpp}
- * namespace references {
+ * namespace length_references {
  * 
  * inline constexpr auto m = reference<dim_length, metre>{};
  * inline constexpr auto km = reference<dim_length, kilometre>{};
  * 
  * }
+ * 
+ * namespace references {
+ * 
+ * using namespace length_references;
+ * 
+ * }
  * @endcode
  * 
  * Quantity references simplify quantity creation:
diff --git a/src/systems/isq-iec80000/include/units/isq/iec80000/modulation_rate.h b/src/systems/isq-iec80000/include/units/isq/iec80000/modulation_rate.h
index 81cd60f1..dc01a6ed 100644
--- a/src/systems/isq-iec80000/include/units/isq/iec80000/modulation_rate.h
+++ b/src/systems/isq-iec80000/include/units/isq/iec80000/modulation_rate.h
@@ -70,7 +70,7 @@ constexpr auto operator"" _q_YBd(unsigned long long l) { gsl_ExpectsAudit(std::i
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace modulation_rate_references {
 
 inline constexpr auto Bd = reference<dim_modulation_rate, baud>{};
 inline constexpr auto kBd = reference<dim_modulation_rate, kilobaud>{};
@@ -82,6 +82,12 @@ inline constexpr auto EBd = reference<dim_modulation_rate, exabaud>{};
 inline constexpr auto ZBd = reference<dim_modulation_rate, zettabaud>{};
 inline constexpr auto YBd = reference<dim_modulation_rate, yottabaud>{};
 
+}  // namespace modulation_rate_references
+
+namespace references {
+
+using namespace modulation_rate_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/isq-iec80000/include/units/isq/iec80000/storage_capacity.h b/src/systems/isq-iec80000/include/units/isq/iec80000/storage_capacity.h
index 88ca062d..285ae84c 100644
--- a/src/systems/isq-iec80000/include/units/isq/iec80000/storage_capacity.h
+++ b/src/systems/isq-iec80000/include/units/isq/iec80000/storage_capacity.h
@@ -127,7 +127,7 @@ constexpr auto operator"" _q_PiB(unsigned long long l) { gsl_ExpectsAudit(std::i
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace storage_capacity_references {
 
 // bits
 inline constexpr auto bit = reference<dim_storage_capacity, iec80000::bit>{};
@@ -167,6 +167,12 @@ inline constexpr auto TiB = reference<dim_storage_capacity, tebibyte>{};
 inline constexpr auto PiB = reference<dim_storage_capacity, pebibyte>{};
 // inline constexpr auto EiB = reference<dim_storage_capacity, exbibyte>{};
 
+}  // namespace storage_capacity_references
+
+namespace references {
+
+using namespace storage_capacity_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/isq-iec80000/include/units/isq/iec80000/traffic_intensity.h b/src/systems/isq-iec80000/include/units/isq/iec80000/traffic_intensity.h
index e74b2c7d..88dad8e5 100644
--- a/src/systems/isq-iec80000/include/units/isq/iec80000/traffic_intensity.h
+++ b/src/systems/isq-iec80000/include/units/isq/iec80000/traffic_intensity.h
@@ -55,10 +55,16 @@ constexpr auto operator"" _q_E(unsigned long long l) { gsl_ExpectsAudit(std::in_
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace traffic_intensity_references {
 
 inline constexpr auto E = reference<dim_traffic_intensity, erlang>{};
 
+}  // namespace traffic_intensity_references
+
+namespace references {
+
+using namespace traffic_intensity_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-cgs/include/units/isq/si/cgs/acceleration.h b/src/systems/si-cgs/include/units/isq/si/cgs/acceleration.h
index 4430d92f..a66213de 100644
--- a/src/systems/si-cgs/include/units/isq/si/cgs/acceleration.h
+++ b/src/systems/si-cgs/include/units/isq/si/cgs/acceleration.h
@@ -54,10 +54,16 @@ constexpr auto operator"" _q_Gal(long double l) { return acceleration<gal, long
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace acceleration_references {
 
 inline constexpr auto Gal = reference<dim_acceleration, gal>{};
 
+}  // namespace acceleration_references
+
+namespace references {
+
+using namespace acceleration_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-cgs/include/units/isq/si/cgs/area.h b/src/systems/si-cgs/include/units/isq/si/cgs/area.h
index b72808b7..89361609 100644
--- a/src/systems/si-cgs/include/units/isq/si/cgs/area.h
+++ b/src/systems/si-cgs/include/units/isq/si/cgs/area.h
@@ -56,10 +56,16 @@ constexpr auto operator"" _q_cm2(long double l) { return area<square_centimetre,
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace area_references {
 
 inline constexpr auto cm2 = reference<dim_area, square_centimetre>{};
 
+}  // namespace area_references
+
+namespace references {
+
+using namespace area_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-cgs/include/units/isq/si/cgs/energy.h b/src/systems/si-cgs/include/units/isq/si/cgs/energy.h
index 808d0802..5abcebe5 100644
--- a/src/systems/si-cgs/include/units/isq/si/cgs/energy.h
+++ b/src/systems/si-cgs/include/units/isq/si/cgs/energy.h
@@ -56,10 +56,16 @@ constexpr auto operator"" _q_erg(long double l) { return energy<erg, long double
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace energy_references {
 
 inline constexpr auto erg = reference<dim_energy, cgs::erg>{};
 
+}  // namespace energy_references
+
+namespace references {
+
+using namespace energy_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-cgs/include/units/isq/si/cgs/force.h b/src/systems/si-cgs/include/units/isq/si/cgs/force.h
index 08619053..579ea978 100644
--- a/src/systems/si-cgs/include/units/isq/si/cgs/force.h
+++ b/src/systems/si-cgs/include/units/isq/si/cgs/force.h
@@ -57,10 +57,16 @@ constexpr auto operator"" _q_dyn(long double l) { return force<dyne, long double
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace force_references {
 
 inline constexpr auto dyn = reference<dim_force, dyne>{};
 
+}  // namespace force_references
+
+namespace references {
+
+using namespace force_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-cgs/include/units/isq/si/cgs/length.h b/src/systems/si-cgs/include/units/isq/si/cgs/length.h
index 722bba47..996d82c0 100644
--- a/src/systems/si-cgs/include/units/isq/si/cgs/length.h
+++ b/src/systems/si-cgs/include/units/isq/si/cgs/length.h
@@ -55,10 +55,16 @@ constexpr auto operator"" _q_cm(long double l) { return length<centimetre, long
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace length_references {
 
 inline constexpr auto cm = reference<dim_length, centimetre>{};
 
+}  // namespace length_references
+
+namespace references {
+
+using namespace length_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-cgs/include/units/isq/si/cgs/mass.h b/src/systems/si-cgs/include/units/isq/si/cgs/mass.h
index 79b5cc9e..6c4012f5 100644
--- a/src/systems/si-cgs/include/units/isq/si/cgs/mass.h
+++ b/src/systems/si-cgs/include/units/isq/si/cgs/mass.h
@@ -55,10 +55,16 @@ constexpr auto operator"" _q_g(long double l) { return mass<gram, long double>(l
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace mass_references {
 
 inline constexpr auto g = reference<dim_mass, gram>{};
 
+}  // namespace mass_references
+
+namespace references {
+
+using namespace mass_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-cgs/include/units/isq/si/cgs/pressure.h b/src/systems/si-cgs/include/units/isq/si/cgs/pressure.h
index 2edf358c..7c43811c 100644
--- a/src/systems/si-cgs/include/units/isq/si/cgs/pressure.h
+++ b/src/systems/si-cgs/include/units/isq/si/cgs/pressure.h
@@ -57,10 +57,16 @@ constexpr auto operator"" _q_Ba(long double l) { return pressure<barye, long dou
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace pressure_references {
 
 inline constexpr auto Ba = reference<dim_pressure, barye>{};
 
+}  // namespace pressure_references
+
+namespace references {
+
+using namespace pressure_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-cgs/include/units/isq/si/cgs/time.h b/src/systems/si-cgs/include/units/isq/si/cgs/time.h
index ff7cfb45..aea13655 100644
--- a/src/systems/si-cgs/include/units/isq/si/cgs/time.h
+++ b/src/systems/si-cgs/include/units/isq/si/cgs/time.h
@@ -49,10 +49,16 @@ using si::literals::operator"" _q_s;
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace time_references {
 
 using si::references::s;
 
+}  // namespace time_references
+
+namespace references {
+
+using namespace time_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-fps/include/units/isq/si/fps/area.h b/src/systems/si-fps/include/units/isq/si/fps/area.h
index 836b1e02..7836e291 100644
--- a/src/systems/si-fps/include/units/isq/si/fps/area.h
+++ b/src/systems/si-fps/include/units/isq/si/fps/area.h
@@ -55,10 +55,16 @@ constexpr auto operator"" _q_ft2(long double l) { return area<square_foot, long
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace area_references {
 
 inline constexpr auto ft2 = reference<dim_area, square_foot>{};
 
+}  // namespace area_references
+
+namespace references {
+
+using namespace area_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-fps/include/units/isq/si/fps/force.h b/src/systems/si-fps/include/units/isq/si/fps/force.h
index ccb61440..25128e60 100644
--- a/src/systems/si-fps/include/units/isq/si/fps/force.h
+++ b/src/systems/si-fps/include/units/isq/si/fps/force.h
@@ -74,12 +74,18 @@ constexpr auto operator"" _q_klbf(long double l) { return force<kilopound_force,
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace force_references {
 
 inline constexpr auto pdl = reference<dim_force, poundal>{};
 inline constexpr auto lbf = reference<dim_force, pound_force>{};
 inline constexpr auto klbf = reference<dim_force, kilopound_force>{};
 
+}  // namespace force_references
+
+namespace references {
+
+using namespace force_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-fps/include/units/isq/si/fps/length.h b/src/systems/si-fps/include/units/isq/si/fps/length.h
index 1e40e0d4..a9ac37ff 100644
--- a/src/systems/si-fps/include/units/isq/si/fps/length.h
+++ b/src/systems/si-fps/include/units/isq/si/fps/length.h
@@ -104,7 +104,7 @@ constexpr auto operator"" _q_naut_mi(long double l) { return length<nautical_mil
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace length_references {
 
 inline constexpr auto thou = reference<dim_length, thousandth>{};
 inline constexpr auto mil = thou;
@@ -117,6 +117,12 @@ inline constexpr auto kyd = reference<dim_length, kiloyard>{};
 inline constexpr auto mile = reference<dim_length, fps::mile>{};
 inline constexpr auto naut_mi = reference<dim_length, nautical_mile>{};
 
+}  // namespace length_references
+
+namespace references {
+
+using namespace length_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-fps/include/units/isq/si/fps/mass.h b/src/systems/si-fps/include/units/isq/si/fps/mass.h
index b6bfdf86..26535de3 100644
--- a/src/systems/si-fps/include/units/isq/si/fps/mass.h
+++ b/src/systems/si-fps/include/units/isq/si/fps/mass.h
@@ -104,7 +104,7 @@ constexpr auto operator"" _q_lton(long double l) { return mass<long_ton, long do
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace mass_references {
 
 inline constexpr auto gr = reference<dim_mass, grain>{};
 inline constexpr auto dr = reference<dim_mass, dram>{};
@@ -116,6 +116,12 @@ inline constexpr auto cwt = reference<dim_mass, hundredweight>{};
 inline constexpr auto ston = reference<dim_mass, short_ton>{};
 inline constexpr auto lton = reference<dim_mass, long_ton>{};
 
+}  // namespace mass_references
+
+namespace references {
+
+using namespace mass_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-fps/include/units/isq/si/fps/power.h b/src/systems/si-fps/include/units/isq/si/fps/power.h
index c797f041..4b3d2458 100644
--- a/src/systems/si-fps/include/units/isq/si/fps/power.h
+++ b/src/systems/si-fps/include/units/isq/si/fps/power.h
@@ -68,10 +68,16 @@ constexpr auto operator"" _q_hp(long double l) { return power<horse_power, long
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace power_references {
 
 inline constexpr auto hp = reference<dim_power, horse_power>{};
 
+}  // namespace power_references
+
+namespace references {
+
+using namespace power_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-fps/include/units/isq/si/fps/pressure.h b/src/systems/si-fps/include/units/isq/si/fps/pressure.h
index 33d3dda6..8cd40b35 100644
--- a/src/systems/si-fps/include/units/isq/si/fps/pressure.h
+++ b/src/systems/si-fps/include/units/isq/si/fps/pressure.h
@@ -71,11 +71,17 @@ constexpr auto operator"" _q_kpsi(long double l) { return pressure<kilopound_for
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace pressure_references {
 
 inline constexpr auto psi = reference<dim_pressure, pound_force_per_inch_sq>{};
 inline constexpr auto kpsi = reference<dim_pressure, kilopound_force_per_inch_sq>{};
 
+}  // namespace pressure_references
+
+namespace references {
+
+using namespace pressure_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-fps/include/units/isq/si/fps/speed.h b/src/systems/si-fps/include/units/isq/si/fps/speed.h
index 700b2daa..f36eb017 100644
--- a/src/systems/si-fps/include/units/isq/si/fps/speed.h
+++ b/src/systems/si-fps/include/units/isq/si/fps/speed.h
@@ -70,11 +70,17 @@ constexpr auto operator"" _q_knot(long double l) { return speed<knot, long doubl
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace speed_references {
 
 inline constexpr auto mph = reference<dim_speed, mile_per_hour>{};
 inline constexpr auto knot = reference<dim_speed, fps::knot>{};
 
+}  // namespace speed_references
+
+namespace references {
+
+using namespace speed_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-fps/include/units/isq/si/fps/time.h b/src/systems/si-fps/include/units/isq/si/fps/time.h
index bd7f7de0..d4f9d4cf 100644
--- a/src/systems/si-fps/include/units/isq/si/fps/time.h
+++ b/src/systems/si-fps/include/units/isq/si/fps/time.h
@@ -53,10 +53,16 @@ using si::literals::operator"" _q_s;
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace time_references {
 
 using si::references::s;
 
+}  // namespace time_references
+
+namespace references {
+
+using namespace time_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-fps/include/units/isq/si/fps/volume.h b/src/systems/si-fps/include/units/isq/si/fps/volume.h
index a4b66fa7..f9d91ba1 100644
--- a/src/systems/si-fps/include/units/isq/si/fps/volume.h
+++ b/src/systems/si-fps/include/units/isq/si/fps/volume.h
@@ -60,11 +60,17 @@ constexpr auto operator"" _q_yd3(long double l) { return volume<cubic_yard, long
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace volume_references {
 
 inline constexpr auto ft3 = reference<dim_volume, cubic_foot>{};
 inline constexpr auto yd3 = reference<dim_volume, cubic_yard>{};
 
+}  // namespace volume_references
+
+namespace references {
+
+using namespace volume_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-iau/include/units/isq/si/iau/length.h b/src/systems/si-iau/include/units/isq/si/iau/length.h
index 521413e3..cfe16dde 100644
--- a/src/systems/si-iau/include/units/isq/si/iau/length.h
+++ b/src/systems/si-iau/include/units/isq/si/iau/length.h
@@ -66,12 +66,18 @@ constexpr auto operator"" _q_angstrom(long double l) { return si::length<angstro
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace length_references {
 
 inline constexpr auto ly = reference<si::dim_length, light_year>{};
 inline constexpr auto pc = reference<si::dim_length, parsec>{};
 inline constexpr auto angstrom = reference<si::dim_length, iau::angstrom>{};
 
+}  // namespace length_references
+
+namespace references {
+
+using namespace length_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-imperial/include/units/isq/si/imperial/length.h b/src/systems/si-imperial/include/units/isq/si/imperial/length.h
index fb1a0366..8af5ad1e 100644
--- a/src/systems/si-imperial/include/units/isq/si/imperial/length.h
+++ b/src/systems/si-imperial/include/units/isq/si/imperial/length.h
@@ -58,11 +58,17 @@ constexpr auto operator"" _q_rd(long double l) { return si::length<rod, long dou
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace length_references {
 
 inline constexpr auto ch = reference<si::dim_length, chain>{};
 inline constexpr auto rd = reference<si::dim_length, rod>{};
 
+}  // namespace length_references
+
+namespace references {
+
+using namespace length_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-international/include/units/isq/si/international/area.h b/src/systems/si-international/include/units/isq/si/international/area.h
index 5e657ad4..05d7b17f 100644
--- a/src/systems/si-international/include/units/isq/si/international/area.h
+++ b/src/systems/si-international/include/units/isq/si/international/area.h
@@ -51,10 +51,16 @@ constexpr auto operator"" _q_ft2(long double l) { return si::area<square_foot, l
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace area_references {
 
 inline constexpr auto ft2 = reference<si::dim_area, square_foot>{};
 
+}  // namespace area_references
+
+namespace references {
+
+using namespace area_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-international/include/units/isq/si/international/length.h b/src/systems/si-international/include/units/isq/si/international/length.h
index 01b7bc16..4607f008 100644
--- a/src/systems/si-international/include/units/isq/si/international/length.h
+++ b/src/systems/si-international/include/units/isq/si/international/length.h
@@ -108,7 +108,7 @@ constexpr auto operator"" _q_mil(long double l) { return si::length<mil, long do
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace length_references {
 
 inline constexpr auto yd = reference<si::dim_length, yard>{};
 inline constexpr auto ft = reference<si::dim_length, foot>{};
@@ -119,6 +119,12 @@ inline constexpr auto mi_naut = reference<si::dim_length, nautical_mile>{};
 inline constexpr auto thou = reference<si::dim_length, international::thou>{};
 inline constexpr auto mil = reference<si::dim_length, international::mil>{};
 
+}  // namespace length_references
+
+namespace references {
+
+using namespace length_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-international/include/units/isq/si/international/volume.h b/src/systems/si-international/include/units/isq/si/international/volume.h
index 69e34a2c..9e03d521 100644
--- a/src/systems/si-international/include/units/isq/si/international/volume.h
+++ b/src/systems/si-international/include/units/isq/si/international/volume.h
@@ -51,10 +51,16 @@ constexpr auto operator"" _q_ft3(long double l) { return si::volume<cubic_foot,
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace volume_references {
 
 inline constexpr auto ft3 = reference<si::dim_volume, cubic_foot>{};
 
+}  // namespace volume_references
+
+namespace references {
+
+using namespace volume_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-typographic/include/units/isq/si/typographic/length.h b/src/systems/si-typographic/include/units/isq/si/typographic/length.h
index 4dc404b1..17467cec 100644
--- a/src/systems/si-typographic/include/units/isq/si/typographic/length.h
+++ b/src/systems/si-typographic/include/units/isq/si/typographic/length.h
@@ -67,13 +67,19 @@ constexpr auto operator"" _q_point_prn(long double l) { return si::length<point_
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace length_references {
 
 inline constexpr auto pica_comp = reference<si::dim_length, typographic::pica_comp>{};
 inline constexpr auto pica_prn = reference<si::dim_length, typographic::pica_prn>{};
 inline constexpr auto point_comp = reference<si::dim_length, typographic::point_comp>{};
 inline constexpr auto point_prn = reference<si::dim_length, typographic::point_prn>{};
 
+}  // namespace length_references
+
+namespace references {
+
+using namespace length_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si-us/include/units/isq/si/us/length.h b/src/systems/si-us/include/units/isq/si/us/length.h
index e34e5454..b115dac6 100644
--- a/src/systems/si-us/include/units/isq/si/us/length.h
+++ b/src/systems/si-us/include/units/isq/si/us/length.h
@@ -67,12 +67,18 @@ constexpr auto operator"" _q_mi_us(long double l) { return si::length<units::isq
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace length_references {
 
 inline constexpr auto ft = reference<si::dim_length, us::foot>{};
 inline constexpr auto fathom = reference<si::dim_length, us::fathom>{};
 inline constexpr auto mi = reference<si::dim_length, us::mile>{};
 
+}  // namespace length_references
+
+namespace references {
+
+using namespace length_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/absorbed_dose.h b/src/systems/si/include/units/isq/si/absorbed_dose.h
index 31d07dea..d2d7e015 100644
--- a/src/systems/si/include/units/isq/si/absorbed_dose.h
+++ b/src/systems/si/include/units/isq/si/absorbed_dose.h
@@ -156,7 +156,7 @@ constexpr auto operator"" _q_YGy(long double l) { return absorbed_dose<yottagray
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace absorbed_dose_references {
 
 inline constexpr auto Gy = reference<dim_absorbed_dose, gray>{};
 inline constexpr auto yGy = reference<dim_absorbed_dose, yoctogray>{};
@@ -180,6 +180,12 @@ inline constexpr auto EGy = reference<dim_absorbed_dose, exagray>{};
 inline constexpr auto ZGy = reference<dim_absorbed_dose, zettagray>{};
 inline constexpr auto YGy = reference<dim_absorbed_dose, yottagray>{};
 
+}  // namespace absorbed_dose_references
+
+namespace references {
+
+using namespace absorbed_dose_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/amount_of_substance.h b/src/systems/si/include/units/isq/si/amount_of_substance.h
index bf066393..433c4f6b 100644
--- a/src/systems/si/include/units/isq/si/amount_of_substance.h
+++ b/src/systems/si/include/units/isq/si/amount_of_substance.h
@@ -55,10 +55,16 @@ constexpr auto operator"" _q_mol(long double l) { return amount_of_substance<mol
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace amount_of_substance_references {
 
 inline constexpr auto mol = reference<dim_amount_of_substance, mole>{};
 
+}  // namespace amount_of_substance_references
+
+namespace references {
+
+using namespace amount_of_substance_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/area.h b/src/systems/si/include/units/isq/si/area.h
index 15732212..ed77183d 100644
--- a/src/systems/si/include/units/isq/si/area.h
+++ b/src/systems/si/include/units/isq/si/area.h
@@ -161,7 +161,7 @@ constexpr auto operator"" _q_ha(long double l) { return area<hectare, long doubl
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace area_references {
 
 inline constexpr auto m2 = reference<dim_area, square_metre>{};
 inline constexpr auto ym2 = reference<dim_area, square_yoctometre>{};
@@ -186,6 +186,12 @@ inline constexpr auto Zm2 = reference<dim_area, square_zettametre>{};
 inline constexpr auto Ym2 = reference<dim_area, square_yottametre>{};
 inline constexpr auto ha = reference<dim_area, hectare>{};
 
+}  // namespace area_references
+
+namespace references {
+
+using namespace area_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/capacitance.h b/src/systems/si/include/units/isq/si/capacitance.h
index 2799c20b..62774493 100644
--- a/src/systems/si/include/units/isq/si/capacitance.h
+++ b/src/systems/si/include/units/isq/si/capacitance.h
@@ -157,7 +157,7 @@ constexpr auto operator"" _q_YF(long double l) { return capacitance<yottafarad,
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace capacitance_references {
 
 inline constexpr auto F = reference<dim_capacitance, farad>{};
 inline constexpr auto yF = reference<dim_capacitance, yoctofarad>{};
@@ -181,6 +181,12 @@ inline constexpr auto EF = reference<dim_capacitance, exafarad>{};
 inline constexpr auto ZF = reference<dim_capacitance, zettafarad>{};
 inline constexpr auto YF = reference<dim_capacitance, yottafarad>{};
 
+}  // namespace capacitance_references
+
+namespace references {
+
+using namespace capacitance_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/catalytic_activity.h b/src/systems/si/include/units/isq/si/catalytic_activity.h
index 6eb94169..f822da23 100644
--- a/src/systems/si/include/units/isq/si/catalytic_activity.h
+++ b/src/systems/si/include/units/isq/si/catalytic_activity.h
@@ -163,7 +163,7 @@ constexpr auto operator"" _q_U(long double l) { return catalytic_activity<enzyme
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace catalytic_activity_references {
 
 inline constexpr auto kat = reference<dim_catalytic_activity, katal>{};
 inline constexpr auto ykat = reference<dim_catalytic_activity, yoctokatal>{};
@@ -188,9 +188,14 @@ inline constexpr auto Zkat = reference<dim_catalytic_activity, zettakatal>{};
 inline constexpr auto Ykat = reference<dim_catalytic_activity, yottakatal>{};
 inline constexpr auto U = reference<dim_catalytic_activity, enzyme_unit>{};
 
+}
+
+namespace references {
+
+using namespace catalytic_activity_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
 
 }  // namespace units::isq::si
-
diff --git a/src/systems/si/include/units/isq/si/conductance.h b/src/systems/si/include/units/isq/si/conductance.h
index b03838c3..8a903af5 100644
--- a/src/systems/si/include/units/isq/si/conductance.h
+++ b/src/systems/si/include/units/isq/si/conductance.h
@@ -136,7 +136,7 @@ constexpr auto operator"" _q_YS(long double l) { return conductance<yottasiemens
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace conductance_references {
 
 inline constexpr auto S = reference<dim_conductance, siemens>{};
 inline constexpr auto yS = reference<dim_conductance, yoctosiemens>{};
@@ -156,6 +156,12 @@ inline constexpr auto ES = reference<dim_conductance, exasiemens>{};
 inline constexpr auto ZS = reference<dim_conductance, zettasiemens>{};
 inline constexpr auto YS = reference<dim_conductance, yottasiemens>{};
 
+}  // namespace conductance_references
+
+namespace references {
+
+using namespace conductance_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/electric_charge.h b/src/systems/si/include/units/isq/si/electric_charge.h
index 7457e2e7..497b12a1 100644
--- a/src/systems/si/include/units/isq/si/electric_charge.h
+++ b/src/systems/si/include/units/isq/si/electric_charge.h
@@ -56,10 +56,16 @@ constexpr auto operator"" _q_C(long double l) { return electric_charge<coulomb,
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace electric_charge_references {
 
 inline constexpr auto C = reference<dim_electric_charge, coulomb>{};
 
+}  // namespace electric_charge_references
+
+namespace references {
+
+using namespace electric_charge_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/electric_current.h b/src/systems/si/include/units/isq/si/electric_current.h
index 236b45b5..a8c3ff74 100644
--- a/src/systems/si/include/units/isq/si/electric_current.h
+++ b/src/systems/si/include/units/isq/si/electric_current.h
@@ -155,7 +155,7 @@ constexpr auto operator"" _q_YA(long double l) { return electric_current<yottaam
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace electric_current_references {
 
 inline constexpr auto A = reference<dim_electric_current, ampere>{};
 inline constexpr auto yA = reference<dim_electric_current, yoctoampere>{};
@@ -179,6 +179,12 @@ inline constexpr auto EA = reference<dim_electric_current, exaampere>{};
 inline constexpr auto ZA = reference<dim_electric_current, zettaampere>{};
 inline constexpr auto YA = reference<dim_electric_current, yottaampere>{};
 
+}  // namespace electric_current_references
+
+namespace references {
+
+using namespace electric_current_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/energy.h b/src/systems/si/include/units/isq/si/energy.h
index bf2a7aaf..9170b42f 100644
--- a/src/systems/si/include/units/isq/si/energy.h
+++ b/src/systems/si/include/units/isq/si/energy.h
@@ -147,7 +147,7 @@ constexpr auto operator"" _q_GeV(long double l) { return energy<gigaelectronvolt
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace energy_references {
 
 inline constexpr auto J = reference<dim_energy, joule>{};
 inline constexpr auto yJ = reference<dim_energy, yoctojoule>{};
@@ -166,9 +166,16 @@ inline constexpr auto PJ = reference<dim_energy, petajoule>{};
 inline constexpr auto EJ = reference<dim_energy, exajoule>{};
 inline constexpr auto ZJ = reference<dim_energy, zettajoule>{};
 inline constexpr auto YJ = reference<dim_energy, yottajoule>{};
+
 inline constexpr auto eV = reference<dim_energy, electronvolt>{};
 inline constexpr auto GeV = reference<dim_energy, gigaelectronvolt>{};
 
+}  // namespace energy_references
+
+namespace references {
+
+using namespace energy_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/force.h b/src/systems/si/include/units/isq/si/force.h
index 4dd17ae2..095f2489 100644
--- a/src/systems/si/include/units/isq/si/force.h
+++ b/src/systems/si/include/units/isq/si/force.h
@@ -157,7 +157,7 @@ constexpr auto operator"" _q_YN(long double l) { return force<yottanewton, long
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace force_references {
 
 inline constexpr auto N = reference<dim_force, newton>{};
 inline constexpr auto yN = reference<dim_force, yoctonewton>{};
@@ -181,6 +181,12 @@ inline constexpr auto EN = reference<dim_force, exanewton>{};
 inline constexpr auto ZN = reference<dim_force, zettanewton>{};
 inline constexpr auto YN = reference<dim_force, yottanewton>{};
 
+}  // namespace force_references
+
+namespace references {
+
+using namespace force_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/frequency.h b/src/systems/si/include/units/isq/si/frequency.h
index 61e4ab9f..90447db8 100644
--- a/src/systems/si/include/units/isq/si/frequency.h
+++ b/src/systems/si/include/units/isq/si/frequency.h
@@ -135,7 +135,7 @@ constexpr auto operator"" _q_YHz(long double l) { return frequency<yottahertz, l
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace frequency_references {
 
 inline constexpr auto Hz = reference<dim_frequency, hertz>{};
 inline constexpr auto yHz = reference<dim_frequency, yoctohertz>{};
@@ -155,6 +155,12 @@ inline constexpr auto EHz = reference<dim_frequency, exahertz>{};
 inline constexpr auto ZHz = reference<dim_frequency, zettahertz>{};
 inline constexpr auto YHz = reference<dim_frequency, yottahertz>{};
 
+}  // namespace frequency_references
+
+namespace references {
+
+using namespace frequency_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/inductance.h b/src/systems/si/include/units/isq/si/inductance.h
index a5853aae..f373952d 100644
--- a/src/systems/si/include/units/isq/si/inductance.h
+++ b/src/systems/si/include/units/isq/si/inductance.h
@@ -137,7 +137,7 @@ constexpr auto operator"" _q_YH(long double l) { return inductance<yottahenry, l
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace inductance_references {
 
 inline constexpr auto H = reference<dim_inductance, henry>{};
 inline constexpr auto yH = reference<dim_inductance, yoctohenry>{};
@@ -157,6 +157,12 @@ inline constexpr auto EH = reference<dim_inductance, exahenry>{};
 inline constexpr auto ZH = reference<dim_inductance, zettahenry>{};
 inline constexpr auto YH = reference<dim_inductance, yottahenry>{};
 
+}  // namespace inductance_references
+
+namespace references {
+
+using namespace inductance_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/length.h b/src/systems/si/include/units/isq/si/length.h
index a608b5ee..d1069252 100644
--- a/src/systems/si/include/units/isq/si/length.h
+++ b/src/systems/si/include/units/isq/si/length.h
@@ -161,7 +161,7 @@ constexpr auto operator"" _q_au(long double l) { return length<astronomical_unit
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace length_references {
 
 inline constexpr auto m = reference<dim_length, metre>{};
 inline constexpr auto ym = reference<dim_length, yoctometre>{};
@@ -186,6 +186,12 @@ inline constexpr auto Zm = reference<dim_length, zettametre>{};
 inline constexpr auto Ym = reference<dim_length, yottametre>{};
 inline constexpr auto au = reference<dim_length, astronomical_unit>{};
 
+}  // namespace length_references
+
+namespace references { 
+
+using namespace length_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/luminous_intensity.h b/src/systems/si/include/units/isq/si/luminous_intensity.h
index cef5eca6..3bd8288f 100644
--- a/src/systems/si/include/units/isq/si/luminous_intensity.h
+++ b/src/systems/si/include/units/isq/si/luminous_intensity.h
@@ -155,7 +155,7 @@ constexpr auto operator"" _q_Ycd(long double l) { return luminous_intensity<yott
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace luminous_intensity_references {
 
 inline constexpr auto cd = reference<dim_luminous_intensity, candela>{};
 inline constexpr auto ycd = reference<dim_luminous_intensity, yoctocandela>{};
@@ -179,6 +179,12 @@ inline constexpr auto Ecd = reference<dim_luminous_intensity, exacandela>{};
 inline constexpr auto Zcd = reference<dim_luminous_intensity, zettacandela>{};
 inline constexpr auto Ycd = reference<dim_luminous_intensity, yottacandela>{};
 
+}  // namespace luminous_intensity_references
+
+namespace references {
+
+using namespace luminous_intensity_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/magnetic_flux.h b/src/systems/si/include/units/isq/si/magnetic_flux.h
index 9c7d6939..44305370 100644
--- a/src/systems/si/include/units/isq/si/magnetic_flux.h
+++ b/src/systems/si/include/units/isq/si/magnetic_flux.h
@@ -137,7 +137,7 @@ constexpr auto operator"" _q_YWb(long double l) { return magnetic_flux<yottawebe
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace magnetic_flux_references {
 
 inline constexpr auto Wb = reference<dim_magnetic_flux, weber>{};
 inline constexpr auto yWb = reference<dim_magnetic_flux, yoctoweber>{};
@@ -157,6 +157,12 @@ inline constexpr auto EWb = reference<dim_magnetic_flux, exaweber>{};
 inline constexpr auto ZWb = reference<dim_magnetic_flux, zettaweber>{};
 inline constexpr auto YWb = reference<dim_magnetic_flux, yottaweber>{};
 
+}  // namespace magnetic_flux_references
+
+namespace references {
+
+using namespace magnetic_flux_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/magnetic_induction.h b/src/systems/si/include/units/isq/si/magnetic_induction.h
index 2d275f73..6b0320ae 100644
--- a/src/systems/si/include/units/isq/si/magnetic_induction.h
+++ b/src/systems/si/include/units/isq/si/magnetic_induction.h
@@ -145,7 +145,7 @@ constexpr auto operator"" _q_G(long double l) { return magnetic_induction<gauss,
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace magnetic_induction_references {
 
 inline constexpr auto T = reference<dim_magnetic_induction, tesla>{};
 inline constexpr auto yT = reference<dim_magnetic_induction, yoctotesla>{};
@@ -166,6 +166,12 @@ inline constexpr auto ZT = reference<dim_magnetic_induction, zettatesla>{};
 inline constexpr auto YT = reference<dim_magnetic_induction, yottatesla>{};
 inline constexpr auto G = reference<dim_magnetic_induction, gauss>{};
 
+}  // namespace magnetic_induction_references
+
+namespace references {
+
+using namespace magnetic_induction_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/mass.h b/src/systems/si/include/units/isq/si/mass.h
index 7a2c248b..32a7d94b 100644
--- a/src/systems/si/include/units/isq/si/mass.h
+++ b/src/systems/si/include/units/isq/si/mass.h
@@ -268,7 +268,7 @@ constexpr auto operator"" _q_Da(long double l) { return mass<dalton, long double
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace mass_references {
 
 inline constexpr auto g = reference<dim_mass, gram>{};
 inline constexpr auto yg = reference<dim_mass, yoctogram>{};
@@ -314,6 +314,12 @@ inline constexpr auto Zt = reference<dim_mass, zettatonne>{};
 inline constexpr auto Yt = reference<dim_mass, yottatonne>{};
 inline constexpr auto Da = reference<dim_mass, dalton>{};
 
+}  // namespace mass_references
+
+namespace references {
+
+using namespace mass_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/power.h b/src/systems/si/include/units/isq/si/power.h
index 0b352b40..d741def6 100644
--- a/src/systems/si/include/units/isq/si/power.h
+++ b/src/systems/si/include/units/isq/si/power.h
@@ -136,7 +136,7 @@ constexpr auto operator"" _q_YW(long double l) { return power<yottawatt, long do
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace power_references {
 
 inline constexpr auto W = reference<dim_power, watt>{};
 inline constexpr auto yW = reference<dim_power, yoctowatt>{};
@@ -156,6 +156,12 @@ inline constexpr auto EW = reference<dim_power, exawatt>{};
 inline constexpr auto ZW = reference<dim_power, zettawatt>{};
 inline constexpr auto YW = reference<dim_power, yottawatt>{};
 
+}  // namespace power_references
+
+namespace references {
+
+using namespace power_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/pressure.h b/src/systems/si/include/units/isq/si/pressure.h
index 9f03d8ac..5ffc6522 100644
--- a/src/systems/si/include/units/isq/si/pressure.h
+++ b/src/systems/si/include/units/isq/si/pressure.h
@@ -157,7 +157,7 @@ constexpr auto operator"" _q_YPa(long double l) { return pressure<yottapascal, l
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace pressure_references {
 
 inline constexpr auto Pa = reference<dim_pressure, pascal>{};
 inline constexpr auto yPa = reference<dim_pressure, yoctopascal>{};
@@ -181,6 +181,12 @@ inline constexpr auto EPa = reference<dim_pressure, exapascal>{};
 inline constexpr auto ZPa = reference<dim_pressure, zettapascal>{};
 inline constexpr auto YPa = reference<dim_pressure, yottapascal>{};
 
+}  // namespace pressure_references
+
+namespace references {
+
+using namespace pressure_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/radioactivity.h b/src/systems/si/include/units/isq/si/radioactivity.h
index 7738f323..7531edd1 100644
--- a/src/systems/si/include/units/isq/si/radioactivity.h
+++ b/src/systems/si/include/units/isq/si/radioactivity.h
@@ -155,7 +155,7 @@ constexpr auto operator"" _q_YBq(long double l) { return radioactivity<yottabecq
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace radioactivity_references {
 
 inline constexpr auto Bq = reference<dim_radioactivity, becquerel>{};
 inline constexpr auto yBq = reference<dim_radioactivity, yoctobecquerel>{};
@@ -179,6 +179,12 @@ inline constexpr auto EBq = reference<dim_radioactivity, exabecquerel>{};
 inline constexpr auto ZBq = reference<dim_radioactivity, zettabecquerel>{};
 inline constexpr auto YBq = reference<dim_radioactivity, yottabecquerel>{};
 
+}  // namespace radioactivity_references
+
+namespace references {
+
+using namespace radioactivity_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/resistance.h b/src/systems/si/include/units/isq/si/resistance.h
index 7d46f76e..cf689bb2 100644
--- a/src/systems/si/include/units/isq/si/resistance.h
+++ b/src/systems/si/include/units/isq/si/resistance.h
@@ -137,7 +137,7 @@ constexpr auto operator"" _q_YR(long double l) { return resistance<yottaohm, lon
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace resistance_references {
 
 inline constexpr auto R = reference<dim_resistance, ohm>{};
 inline constexpr auto yR = reference<dim_resistance, yoctoohm>{};
@@ -157,6 +157,12 @@ inline constexpr auto ER = reference<dim_resistance, exaohm>{};
 inline constexpr auto ZR = reference<dim_resistance, zettaohm>{};
 inline constexpr auto YR = reference<dim_resistance, yottaohm>{};
 
+}  // namespace resistance_references
+
+namespace references {
+
+using namespace resistance_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/thermodynamic_temperature.h b/src/systems/si/include/units/isq/si/thermodynamic_temperature.h
index 902dbc62..f2bbf7cf 100644
--- a/src/systems/si/include/units/isq/si/thermodynamic_temperature.h
+++ b/src/systems/si/include/units/isq/si/thermodynamic_temperature.h
@@ -54,10 +54,16 @@ constexpr auto operator"" _q_K(long double l) { return thermodynamic_temperature
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace thermodynamic_temperature_references {
 
 inline constexpr auto K = reference<dim_thermodynamic_temperature, kelvin>{};
 
+}  // namespace thermodynamic_temperature_references
+
+namespace references {
+
+using namespace thermodynamic_temperature_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/time.h b/src/systems/si/include/units/isq/si/time.h
index bfc2e13c..82f9febe 100644
--- a/src/systems/si/include/units/isq/si/time.h
+++ b/src/systems/si/include/units/isq/si/time.h
@@ -110,7 +110,7 @@ constexpr auto operator"" _q_d(long double l) { return time<day, long double>(l)
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace time_references {
 
 inline constexpr auto ys = reference<dim_time, yoctosecond>{};
 inline constexpr auto zs = reference<dim_time, zeptosecond>{};
@@ -125,7 +125,13 @@ inline constexpr auto min = reference<dim_time, minute>{};
 inline constexpr auto h = reference<dim_time, hour>{};
 inline constexpr auto d = reference<dim_time, day>{};
 
-}  // namespace references
+}  // namespace time_references
+
+namespace references {
+
+using namespace time_references;
+
+} // namespace references
 
 #endif // UNITS_REFERENCES
 
diff --git a/src/systems/si/include/units/isq/si/voltage.h b/src/systems/si/include/units/isq/si/voltage.h
index 8d323900..a124f1fe 100644
--- a/src/systems/si/include/units/isq/si/voltage.h
+++ b/src/systems/si/include/units/isq/si/voltage.h
@@ -157,7 +157,7 @@ constexpr auto operator"" _q_YV(long double l) { return voltage<yottavolt, long
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace voltage_references {
 
 inline constexpr auto V = reference<dim_voltage, volt>{};
 inline constexpr auto yV = reference<dim_voltage, yoctovolt>{};
@@ -181,6 +181,12 @@ inline constexpr auto EV = reference<dim_voltage, exavolt>{};
 inline constexpr auto ZV = reference<dim_voltage, zettavolt>{};
 inline constexpr auto YV = reference<dim_voltage, yottavolt>{};
 
+}  // namespace voltage_references
+
+namespace references {
+
+using namespace voltage_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES
diff --git a/src/systems/si/include/units/isq/si/volume.h b/src/systems/si/include/units/isq/si/volume.h
index 505f7f31..dc6bdfe8 100644
--- a/src/systems/si/include/units/isq/si/volume.h
+++ b/src/systems/si/include/units/isq/si/volume.h
@@ -261,7 +261,7 @@ constexpr auto operator"" _q_Yl(long double l) { return volume<yottalitre, long
 
 #ifdef UNITS_REFERENCES
 
-namespace references {
+namespace volume_references {
 
 inline constexpr auto m3 = reference<dim_volume, cubic_metre>{};
 inline constexpr auto ym3 = reference<dim_volume, cubic_yoctometre>{};
@@ -306,6 +306,12 @@ inline constexpr auto El = reference<dim_volume, exalitre>{};
 inline constexpr auto Zl = reference<dim_volume, zettalitre>{};
 inline constexpr auto Yl = reference<dim_volume, yottalitre>{};
 
+}  // namespace volume_references
+
+namespace references {
+
+using namespace volume_references;
+
 }  // namespace references
 
 #endif // UNITS_REFERENCES