examples, alternative namespaces : Part2 of put alternative namespace definitions in local headers.

examples, clcpp_response,alternative_namespaces::clcpp_response : use fmt functions for showing precision of quantities
examples, alternative namespaces : combined the alternative namespace quantity typedefs in header files.
examples, alternative namespaces : add simple timer example

example/alternative_namespaces/CMakeLists.txt

@@ -29,3 +29,4 @@ add_example(box_example)
 add_example(capacitor_time_curve)
 add_example(clcpp_response)
 add_example(conversion_factor)
+add_example(timer)

example/alternative_namespaces/area.h

@@ -0,0 +1,14 @@
+
+#pragma once
+
+#include <units/physical/si/area.h>
+
+namespace area {
+
+template<typename Rep = double>
+using m2 = units::si::area<units::si::square_metre, Rep>;
+
+template<typename Rep = double>
+using fm2 = units::si::area<units::si::square_femtometre, Rep>;
+
+}  // namespace area

example/alternative_namespaces/box_example.cpp

@@ -11,7 +11,6 @@
 
 using namespace units::experimental;
 
-
 struct Box {
 
   static constexpr auto air_density = density::kg_per_m3<>{1.225};

example/alternative_namespaces/capacitor_time_curve.cpp

@@ -23,31 +23,11 @@
 #include <units/physical/si/capacitance.h>
 #include <units/physical/si/resistance.h>
 #include <units/physical/si/time.h>
-#include <units/physical/si/voltage.h>
+#include "./voltage.h"
 #include <cmath>
 #include <iostream>
 
-namespace {
-namespace voltage {
-
-template<typename Rep = double>
-using V = units::si::voltage<units::si::volt, Rep>;
-
-template<typename Rep = double>
-using mV = units::si::voltage<units::si::millivolt, Rep>;
-
-template<typename Rep = double>
-using uV = units::si::voltage<units::si::microvolt, Rep>;
-
-template<typename Rep = double>
-using nV = units::si::voltage<units::si::nanovolt, Rep>;
-
-template<typename Rep = double>
-using pV = units::si::voltage<units::si::picovolt, Rep>;
-
-}  // namespace voltage
-}  // namespace
-
+using namespace units::experimental;
 using namespace units::si::literals;
 
 int main()

example/alternative_namespaces/clcpp_response.cpp

@@ -15,127 +15,30 @@
  along with this program. If not, see http://www.gnu.org/licenses./
 */
 
-#include <units/physical/iau/length.h>
-#include <units/physical/imperial/length.h>
-#include <units/physical/international/length.h>
-#include <units/physical/si/area.h>
-#include <units/physical/si/length.h>
-#include <units/physical/si/time.h>
-#include <units/physical/si/volume.h>
-#include <units/physical/typographic/length.h>
-#include <units/physical/us/length.h>
 #include <iostream>
+#include <units/format.h>
 
-namespace {
-namespace length {
-
-template<typename Rep = double>
-using m = units::si::length<units::si::metre, Rep>;
-
-template<typename Rep = double>
-using mm = units::si::length<units::si::millimetre, Rep>;
-
-template<typename Rep = double>
-using fm = units::si::length<units::si::femtometre, Rep>;
-
-template<typename Rep = double>
-using km = units::si::length<units::si::kilometre, Rep>;
-
-template<typename Rep = double>
-using AU = units::si::length<units::si::astronomical_unit, Rep>;
-
-template<typename Rep = double>
-using in = units::si::length<units::international::inch, Rep>;
-
-template<typename Rep = double>
-using angstrom = units::si::length<units::iau::angstrom, Rep>;
-
-template<typename Rep = double>
-using ch = units::si::length<units::imperial::chain, Rep>;
-
-template<typename Rep = double>
-using fathom = units::si::length<units::international::fathom, Rep>;
-
-template<typename Rep = double>
-using fathom_us = units::si::length<units::us::fathom, Rep>;
-
-template<typename Rep = double>
-using ft = units::si::length<units::international::foot, Rep>;
-
-template<typename Rep = double>
-using ft_us = units::si::length<units::us::foot, Rep>;
-
-template<typename Rep = double>
-using ly = units::si::length<units::iau::light_year, Rep>;
-
-template<typename Rep = double>
-using mi = units::si::length<units::international::mile, Rep>;
-
-template<typename Rep = double>
-using mi_naut = units::si::length<units::international::nautical_mile, Rep>;
-
-template<typename Rep = double>
-using pc = units::si::length<units::iau::parsec, Rep>;
-
-template<typename Rep = double>
-using pica_comp = units::si::length<units::typographic::pica_comp, Rep>;
-
-template<typename Rep = double>
-using pica_prn = units::si::length<units::typographic::pica_prn, Rep>;
-
-template<typename Rep = double>
-using point_comp = units::si::length<units::typographic::point_comp, Rep>;
-
-template<typename Rep = double>
-using point_prn = units::si::length<units::typographic::point_prn, Rep>;
-
-template<typename Rep = double>
-using rd = units::si::length<units::imperial::rod, Rep>;
-
-template<typename Rep = double>
-using yd = units::si::length<units::international::yard, Rep>;
-
-}  // namespace length
-
-namespace time {
-
-template<typename Rep = double>
-using s = units::si::time<units::si::second, Rep>;
-
-template<typename Rep = double>
-using min = units::si::time<units::si::minute, Rep>;
-
-template<typename Rep = double>
-using h = units::si::time<units::si::hour, Rep>;
-
-}  // namespace time
-
-namespace area {
-
-template<typename Rep = double>
-using m2 = units::si::area<units::si::square_metre, Rep>;
-
-template<typename Rep = double>
-using fm2 = units::si::area<units::si::square_femtometre, Rep>;
-
-}  // namespace area
-}  // namespace
-
+#include "./length.h"
+#include "./volume.h"
+#include "./time.h"
+#include "./area.h"
+#include "./units_str.h"
 
 using namespace units::si::literals;
 using namespace units::international;
+using namespace units::experimental;
 
 void simple_quantities()
 {
   using distance = length::m<>;
-  using time = time::s<>;
+  using q_time = q_time::s<>;
 
   constexpr distance km = 1.0q_km;
   constexpr distance miles = 1.0q_mi;
 
-  constexpr time sec = 1q_s;
-  constexpr time min = 1q_min;
-  constexpr time hr = 1q_h;
+  constexpr q_time sec = 1q_s;
+  constexpr q_time min = 1q_min;
+  constexpr q_time hr = 1q_h;
 
   std::cout << "A physical quantities library can choose the simple\n";
   std::cout << "option to provide output using a single type for each base unit:\n\n";
@@ -151,11 +54,9 @@ void quantities_with_typed_units()
   constexpr length::km<> km = 1.0q_km;
   constexpr length::mi<> miles = 1.0q_mi;
 
-  std::cout.precision(6);
-
-  constexpr time::s<> sec = 1q_s;
-  constexpr time::min<> min = 1q_min;
-  constexpr time::h<> hr = 1q_h;
+  constexpr q_time::s<> sec = 1q_s;
+  constexpr q_time::min<> min = 1q_min;
+  constexpr q_time::h<> hr = 1q_h;
 
   std::cout << "A more flexible option is to provide separate types for each unit,\n\n";
   std::cout << km << '\n';
@@ -192,16 +93,14 @@ void quantities_with_typed_units()
 
 void calcs_comparison()
 {
-  std::cout.precision(20);
   std::cout << "\nA distinct unit for each type is efficient and accurate\n"
                "when adding two values of the same very big\n"
                "or very small type:\n\n";
 
-  length::fm<float> L1A = 2q_fm;
-  length::fm<float> L2A = 3q_fm;
+  length::fm<float> L1A = 2.q_fm;
+  length::fm<float> L2A = 3.q_fm;
   length::fm<float> LrA = L1A + L2A;
-
-  std::cout << L1A << " + " << L2A << " = " << LrA << "\n\n";
+  fmt::print("{:%.30Q %q}\n + {:%.30Q %q}\n   = {:%.30Q %q}\n\n",L1A,L2A,LrA);
 
   std::cout << "The single unit method must convert large\n"
                "or small values in other units to the base unit.\n"
@@ -210,23 +109,22 @@ void calcs_comparison()
   length::m<float> L1B = L1A;
   length::m<float> L2B = L2A;
   length::m<float> LrB = L1B + L2B;
-
-  std::cout << L1B << " + " << L2B << " = " << LrB << "\n\n";
+  fmt::print("{:%.30Q %q}\n + {:%.30Q %q}\n   = {:%.30Q %q}\n\n",L1B,L2B,LrB);
 
   std::cout << "In multiplication and division:\n\n";
 
   area::fm2<float> ArA = L1A * L2A;
-  std::cout << L1A << " * " << L2A << " = " << ArA << "\n\n";
+  fmt::print("{:%.30Q %q}\n * {:%.30Q %q}\n   = {:%.30Q %q}\n\n",L1A,L2A,ArA);
 
   std::cout << "similar problems arise\n\n";
 
   area::m2<float> ArB = L1B * L2B;
-  std::cout << L1B << " * " << L2B << "\n = " << ArB << '\n';
+  fmt::print("{:%.30Q %q}\n * {:%.30Q %q}\n   = {:%.30Q %q}\n\n",L1B,L2B,ArB);
 }
 
 int main()
 {
-  std::cout << "This demo was originally posted on com.lang.c++.moderated in 2006\n";
+  std::cout << "This demo was originally posted on comp.lang.c++.moderated in 2006\n";
   std::cout << "http://compgroups.net/comp.lang.c++.moderated/dimensional-analysis-units/51712\n";
   std::cout << "Here converted to use mpusz/units library.\n\n";
 

example/alternative_namespaces/conversion_factor.cpp

@@ -15,7 +15,9 @@
  along with this program. If not, see http://www.gnu.org/licenses./
 */
 
-#include <units/physical/si/length.h>
+
+#include "./units_str.h"
+#include "./length.h"
 #include <iostream>
 
 /*
@@ -36,29 +38,10 @@ inline constexpr std::common_type_t<typename Target::rep, typename Source::rep>
   return target{source{1}}.count();
 }
 
-// get at the units text of the quantity, without its numeric value
-inline auto constexpr units_str(const units::Quantity AUTO& q)
-{
-  typedef std::remove_cvref_t<decltype(q)> qtype;
-  return units::detail::unit_text<typename qtype::dimension, typename qtype::unit>();
-}
-
-}  // namespace
-
-namespace {
-
-namespace length {
-
-template<typename Rep = double>
-using m = units::si::length<units::si::metre, Rep>;
-
-template<typename Rep = double>
-using mm = units::si::length<units::si::millimetre, Rep>;
-
-}  // namespace length
 }  // namespace
 
 using namespace units::si::literals;
+using namespace units::experimental;
 
 int main()
 {

example/alternative_namespaces/length.h

@@ -3,6 +3,11 @@
 #pragma once
 
 #include <units/physical/si/length.h>
+#include <units/physical/imperial/length.h>
+#include <units/physical/international/length.h>
+#include <units/physical/typographic/length.h>
+#include <units/physical/us/length.h>
+#include <units/physical/iau/length.h>
 
 namespace units{
 namespace experimental{
@@ -15,6 +20,67 @@ using m = units::si::length<units::si::metre, Rep>;
 template<typename Rep = double>
 using mm = units::si::length<units::si::millimetre, Rep>;
 
+template<typename Rep = double>
+using fm = units::si::length<units::si::femtometre, Rep>;
+
+template<typename Rep = double>
+using km = units::si::length<units::si::kilometre, Rep>;
+
+template<typename Rep = double>
+using AU = units::si::length<units::si::astronomical_unit, Rep>;
+
+template<typename Rep = double>
+using in = units::si::length<units::international::inch, Rep>;
+
+template<typename Rep = double>
+using angstrom = units::si::length<units::iau::angstrom, Rep>;
+
+template<typename Rep = double>
+using ch = units::si::length<units::imperial::chain, Rep>;
+
+template<typename Rep = double>
+using fathom = units::si::length<units::international::fathom, Rep>;
+
+template<typename Rep = double>
+using fathom_us = units::si::length<units::us::fathom, Rep>;
+
+template<typename Rep = double>
+using ft = units::si::length<units::international::foot, Rep>;
+
+template<typename Rep = double>
+using ft_us = units::si::length<units::us::foot, Rep>;
+
+template<typename Rep = double>
+using ly = units::si::length<units::iau::light_year, Rep>;
+
+template<typename Rep = double>
+using mi = units::si::length<units::international::mile, Rep>;
+
+template<typename Rep = double>
+using mi_naut = units::si::length<units::international::nautical_mile, Rep>;
+
+template<typename Rep = double>
+using pc = units::si::length<units::iau::parsec, Rep>;
+
+template<typename Rep = double>
+using pica_comp = units::si::length<units::typographic::pica_comp, Rep>;
+
+template<typename Rep = double>
+using pica_prn = units::si::length<units::typographic::pica_prn, Rep>;
+
+template<typename Rep = double>
+using point_comp = units::si::length<units::typographic::point_comp, Rep>;
+
+template<typename Rep = double>
+using point_prn = units::si::length<units::typographic::point_prn, Rep>;
+
+template<typename Rep = double>
+using rd = units::si::length<units::imperial::rod, Rep>;
+
+template<typename Rep = double>
+using yd = units::si::length<units::international::yard, Rep>;
+
+
 }  // namespace length
 
 }} // units::experimental

example/alternative_namespaces/time.h

@@ -0,0 +1,21 @@
+
+#pragma once
+
+#include <units/physical/si/time.h>
+
+// named qtime due to conflict with time_t time(time_t*)
+namespace q_time {
+
+template<typename Rep = double>
+using s = units::si::time<units::si::second, Rep>;
+
+template<typename Rep = double>
+using ms = units::si::time<units::si::millisecond, Rep>;
+
+template<typename Rep = double>
+using min = units::si::time<units::si::minute, Rep>;
+
+template<typename Rep = double>
+using h = units::si::time<units::si::hour, Rep>;
+
+}  // namespace time

example/alternative_namespaces/timer.cpp

@@ -0,0 +1,35 @@
+
+#include <iostream>
+#include "./timer.h"
+
+/*
+   simple timer, useful for perf timing etc
+*/
+
+using namespace units::experimental;
+using namespace units::si::literals;
+
+int main()
+{
+   std::cout << "Simple timer using mpusz/units ...\n";
+
+   auto const period = 0.5q_s;
+   auto const duration = 10 * period;
+
+   timer t;
+
+   auto const start_time = t();
+
+   std::cout << "Started at " << start_time <<'\n';
+
+   auto prev = start_time;
+   for (auto now = t(); (now - start_time) < duration; now = t() ) {
+      if ( (now - prev ) >= period ){
+         prev = now;
+         std::cout << "tick (" << now << ")\n";;
+      }
+   }
+   t.stop();
+
+   std::cout << "finished at " << t() << '\n';
+}

example/alternative_namespaces/timer.h

@@ -0,0 +1,64 @@
+#pragma once
+
+/*
+ Copyright (c) 2003-2020 Andy Little.
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see http://www.gnu.org/licenses./
+ */
+
+#include "./time.h"
+
+#include <ctime>
+
+namespace units{ namespace experimental{
+ 
+    class timer{
+        
+    public:
+        timer(): running(true)
+        {
+            start_time = std::clock();
+        }
+
+        void restart() 
+        {
+            running = true;
+            start_time = std::clock();
+        }
+
+        void stop() 
+        {
+            if (running){
+                stop_time = std::clock();
+                running = false;
+            }
+        }
+        
+        q_time::ms<> operator ()()const
+        {
+            std::clock_t const wanted = running ? std::clock() : stop_time;
+            static constexpr auto divider = 1000.0 / CLOCKS_PER_SEC;
+           
+            return q_time::ms<>( 
+                difftime(wanted , start_time) 
+            ) * divider;
+        }
+        bool is_running() const {return running;}
+        bool is_stopped() const {return !running;}
+    private:
+        bool running;
+        std::clock_t start_time,stop_time;
+    };
+
+} }//units::experimental

example/alternative_namespaces/units_str.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#include <units/physical/dimensions.h>
+#include <units/physical/si/prefixes.h>
+#include <units/quantity.h>
+// get at the units text of the quantity, without its numeric value
+inline auto constexpr units_str(const units::Quantity AUTO& q)
+{
+  typedef std::remove_cvref_t<decltype(q)> qtype;
+  return units::detail::unit_text<typename qtype::dimension, typename qtype::unit>();
+}

example/alternative_namespaces/voltage.h

@@ -0,0 +1,31 @@
+
+
+#pragma once
+
+#include <units/physical/si/voltage.h>
+
+namespace units{
+namespace experimental{
+
+namespace voltage {
+
+template<typename Rep = double>
+using V = units::si::voltage<units::si::volt, Rep>;
+
+template<typename Rep = double>
+using mV = units::si::voltage<units::si::millivolt, Rep>;
+
+template<typename Rep = double>
+using uV = units::si::voltage<units::si::microvolt, Rep>;
+
+template<typename Rep = double>
+using nV = units::si::voltage<units::si::nanovolt, Rep>;
+
+template<typename Rep = double>
+using pV = units::si::voltage<units::si::picovolt, Rep>;
+
+}  // namespace voltage
+
+}} // units::experimental
+
+

example/clcpp_response.cpp

@@ -24,6 +24,7 @@
 #include <units/physical/si/volume.h>
 #include <units/physical/typographic/length.h>
 #include <units/physical/us/length.h>
+#include <units/format.h>
 #include <iostream>
 
 namespace {
@@ -105,36 +106,33 @@ void calcs_comparison()
 {
   using namespace units::si;
 
-  std::cout.precision(20);
   std::cout << "\nA distinct unit for each type is efficient and accurate\n"
                "when adding two values of the same very big\n"
                "or very small type:\n\n";
 
-  Length AUTO L1A = 2.q_fm;
-  Length AUTO L2A = 3.q_fm;
-  Length AUTO LrA = L1A + L2A;
-
-  std::cout << L1A << " + " << L2A << " = " << LrA << "\n\n";
+  length<femtometre,float> L1A = 2.q_fm;
+  length<femtometre,float> L2A = 3.q_fm;
+  length<femtometre,float> LrA = L1A + L2A;
+  fmt::print("{:%.30Q %q}\n + {:%.30Q %q}\n   = {:%.30Q %q}\n\n",L1A,L2A,LrA);
 
   std::cout << "The single unit method must convert large\n"
                "or small values in other units to the base unit.\n"
                "This is both inefficient and inaccurate\n\n";
 
-  length<metre> L1B = L1A;
-  length<metre> L2B = L2A;
-  length<metre> LrB = L1B + L2B;
-
-  std::cout << L1B << " + " << L2B << " = " << LrB << "\n\n";
+  length<metre,float> L1B = L1A;
+  length<metre,float> L2B = L2A;
+  length<metre,float> LrB = L1B + L2B;
+  fmt::print("{:%.30Q %q}\n + {:%.30Q %q}\n   = {:%.30Q %q}\n\n",L1B,L2B,LrB);
 
   std::cout << "In multiplication and division:\n\n";
 
-  Area AUTO ArA = L1A * L2A;
-  std::cout << L1A << " * " << L2A << " = " << ArA << "\n\n";
+  area<square_femtometre,float> ArA = L1A * L2A;
+  fmt::print("{:%.30Q %q}\n * {:%.30Q %q}\n   = {:%.30Q %q}\n\n",L1A,L2A,ArA);
 
   std::cout << "similar problems arise\n\n";
 
-  Area AUTO ArB = L1B * L2B;
-  std::cout << L1B << " * " << L2B << "\n = " << ArB << '\n';
+  area<square_metre,float> ArB = L1B * L2B;
+  fmt::print("{:%.30Q %q}\n * {:%.30Q %q}\n   = {:%.30Q %q}\n\n",L1B,L2B,ArB);
 }
 
 }  // namespace