feat: custom systems examples added

docs/CMakeLists.txt

@@ -88,6 +88,7 @@ add_custom_command(OUTPUT "${SPHINX_INDEX_FILE}"
                        "${CMAKE_CURRENT_SOURCE_DIR}/examples/capacitor_time_curve.rst"
                        "${CMAKE_CURRENT_SOURCE_DIR}/examples/clcpp_response.rst"
                        "${CMAKE_CURRENT_SOURCE_DIR}/examples/conversion_factor.rst"
+                       "${CMAKE_CURRENT_SOURCE_DIR}/examples/custom_systems.rst"
                        "${CMAKE_CURRENT_SOURCE_DIR}/examples/foot_pound_second.rst"
                        "${CMAKE_CURRENT_SOURCE_DIR}/examples/glide_computer.rst"
                        "${CMAKE_CURRENT_SOURCE_DIR}/examples/hello_units.rst"

docs/examples.rst

@@ -11,6 +11,7 @@ Examples
     examples/measurement
     examples/linear_algebra
     examples/foot_pound_second
+    examples/custom_systems
     examples/glide_computer
 
     examples/capacitor_time_curve

docs/examples/custom_systems.rst

@@ -0,0 +1,7 @@
+custom_systems
+==============
+
+.. literalinclude:: ../../example/custom_systems.cpp
+  :caption: custom_systems.cpp
+  :start-at: #include
+  :linenos:

example/CMakeLists.txt

@@ -31,6 +31,7 @@ add_example(box_example)
 add_example(capacitor_time_curve)
 add_example(clcpp_response)
 add_example(conversion_factor)
+add_example(custom_systems)
 add_example(experimental_angle)
 add_example(foot_pound_second)
 add_example(kalman_filter-alpha_beta_filter_example2)

example/custom_systems.cpp

@@ -0,0 +1,108 @@
+// The MIT License (MIT)
+//
+// Copyright (c) 2018 Mateusz Pusz
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+#include <units/quantity.h>
+#include <units/physical/si/prefixes.h>
+#include <iostream>
+
+using namespace units;
+
+namespace fps {
+
+struct foot : named_unit<foot, "ft", no_prefix> {};
+struct yard : named_scaled_unit<yard, "yd", no_prefix, ratio(3), foot> {};
+
+struct dim_length : base_dimension<"L", foot> {};
+
+template<Unit U, ScalableNumber Rep = double>
+using length = quantity<dim_length, U, Rep>;
+
+}  // namespace fps
+
+namespace si {
+
+struct metre : named_unit<metre, "m", units::physical::si::prefix> {};
+struct kilometre : prefixed_unit<kilometre, units::physical::si::kilo, metre> {};
+
+struct dim_length : base_dimension<"L", metre> {};
+
+template<Unit U, ScalableNumber Rep = double>
+using length = quantity<dim_length, U, Rep>;
+
+namespace fps {
+
+struct foot : named_scaled_unit<foot, "ft", no_prefix, ratio(3'048, 1'000, -1), metre> {};
+struct yard : named_scaled_unit<yard, "yd", no_prefix, ratio(3), foot> {};
+
+struct dim_length : base_dimension<"L", foot> {};
+
+template<Unit U, ScalableNumber Rep = double>
+using length = quantity<dim_length, U, Rep>;
+
+}  // namespace fps
+}  // namespace si
+
+void conversions()
+{
+  // constexpr auto fps_yard = fps::length<fps::yard>(1.);
+  // std::cout << quantity_cast<si::kilometre>(fps_yard) << "\n";
+
+  constexpr auto si_fps_yard = si::fps::length<si::fps::yard>(1.);
+  std::cout << quantity_cast<si::kilometre>(si_fps_yard) << "\n";
+}
+
+void unknown_dimensions()
+{
+  constexpr auto fps_yard = fps::length<fps::yard>(1.);
+  constexpr auto fps_area = quantity_cast<unknown_coherent_unit>(fps_yard * fps_yard);
+  std::cout << fps_yard << "\n";
+  std::cout << fps_area << "\n";
+
+  constexpr auto si_fps_yard = si::fps::length<si::fps::yard>(1.);
+  constexpr auto si_fps_area = quantity_cast<unknown_coherent_unit>(si_fps_yard * si_fps_yard);
+  std::cout << si_fps_yard << "\n";
+  std::cout << si_fps_area << "\n";
+}
+
+std::ostream& operator<<(std::ostream& os, const ratio& r)
+{
+  return os << "ratio{" << r.num << ", " << r.den << ", " << r.exp << "}";
+}
+
+std::ostream& operator<<(std::ostream& os, const Unit auto& u)
+{
+  using unit_type = std::remove_cvref_t<decltype(u)>;
+  return os << unit_type::ratio << " x " << unit_type::reference::symbol.standard();
+}
+
+void what_is_your_ratio()
+{
+  std::cout << "fps:     " << fps::yard() << "\n";
+  std::cout << "si::fps: " << si::fps::yard() << "\n";
+}
+
+int main()
+{
+  conversions();
+  unknown_dimensions();
+  what_is_your_ratio();
+}