refactor: conversion_factor example moved to the main examples directory

docs/examples/conversion_factor.rst

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

example/CMakeLists.txt

@@ -22,11 +22,17 @@
 
 cmake_minimum_required(VERSION 3.2)
 
-add_executable(hello_units hello_units.cpp)
+#
-target_link_libraries(hello_units PRIVATE mp-units::core-fmt mp-units::core-io mp-units::si mp-units::si-international)
+# add_example(target <depependencies>...)
+#
+function(add_example target)
+    add_executable(${target} ${target}.cpp)
+    target_link_libraries(${target} PRIVATE ${ARGN})
+endfunction()
 
-add_executable(custom_systems custom_systems.cpp)
+add_example(conversion_factor mp-units::core-fmt mp-units::core-io mp-units::si)
-target_link_libraries(custom_systems PRIVATE mp-units::core-io mp-units::si)
+add_example(custom_systems mp-units::core-io mp-units::si)
+add_example(hello_units mp-units::core-fmt mp-units::core-io mp-units::si mp-units::si-international)
 
 if(NOT UNITS_LIBCXX)
     add_subdirectory(glide_computer)

example/conversion_factor.cpp

@@ -46,7 +46,7 @@ int main()
 
   std::cout << "conversion factor in mp-units...\n\n";
 
-  constexpr length<metre> lengthA = 2.0_q_m;
+  constexpr length<metre> lengthA(2.0);
   constexpr length<millimetre> lengthB = lengthA;
 
   std::cout << fmt::format("lengthA( {} ) and lengthB( {} )\n", lengthA, lengthB)

example/literals/CMakeLists.txt

@@ -35,7 +35,6 @@ add_example(avg_speed mp-units::core-io mp-units::si mp-units::si-cgs mp-units::
 add_example(box_example mp-units::core-fmt mp-units::si)
 add_example(capacitor_time_curve mp-units::core-io mp-units::si)
 add_example(clcpp_response mp-units::core-fmt mp-units::core-io mp-units::si mp-units::si-iau mp-units::si-imperial mp-units::si-international mp-units::si-typographic mp-units::si-us)
-add_example(conversion_factor mp-units::core-fmt mp-units::core-io mp-units::si)
 add_example(experimental_angle mp-units::core-fmt mp-units::core-io mp-units::si)
 add_example(foot_pound_second mp-units::core-fmt mp-units::si-fps)
 add_example(kalman_filter-alpha_beta_filter_example2 mp-units::core-fmt mp-units::si)

example/references/CMakeLists.txt

@@ -35,7 +35,6 @@ add_example(avg_speed mp-units::core-io mp-units::si mp-units::si-cgs mp-units::
 add_example(box_example mp-units::core-fmt mp-units::si)
 add_example(capacitor_time_curve mp-units::core-io mp-units::si)
 add_example(clcpp_response mp-units::core-fmt mp-units::core-io mp-units::si mp-units::si-iau mp-units::si-imperial mp-units::si-international mp-units::si-typographic mp-units::si-us)
-add_example(conversion_factor mp-units::core-fmt mp-units::core-io mp-units::si)
 add_example(experimental_angle mp-units::core-fmt mp-units::core-io mp-units::si)
 add_example(foot_pound_second mp-units::core-fmt mp-units::si-fps)
 add_example(kalman_filter-alpha_beta_filter_example2 mp-units::core-fmt mp-units::si)

example/references/conversion_factor.cpp

@@ -1,61 +0,0 @@
-/*
- 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 <units/format.h>
-#include <units/isq/si/length.h>
-#include <iostream>
-#include <type_traits>
-
-/*
-  get conversion factor from one dimensionally equivalent
-  quantity type to another
-*/
-
-namespace {
-
-template<units::Quantity Target, units::Quantity Source>
-  requires units::equivalent<typename Source::dimension, typename Target::dimension>
-inline constexpr std::common_type_t<typename Target::rep, typename Source::rep> conversion_factor(Target, Source)
-{
-  // get quantities looking like inputs but with Q::rep that doesn't have narrowing conversion
-  typedef std::common_type_t<typename Target::rep, typename Source::rep> rep;
-  typedef units::quantity<typename Source::dimension, typename Source::unit, rep> source;
-  typedef units::quantity<typename Target::dimension, typename Target::unit, rep> target;
-  return target{source{1}}.number();
-}
-
-}  // namespace
-
-int main()
-{
-  using namespace units::isq::si;
-  using namespace units::isq::si::references;
-
-  std::cout << "conversion factor in mp-units...\n\n";
-
-  constexpr auto lengthA = 2.0 * m;
-  constexpr auto lengthB = quantity_cast<millimetre>(lengthA);
-
-  std::cout << fmt::format("lengthA( {} ) and lengthB( {} )\n", lengthA, lengthB)
-            << "represent the same length in different units.\n\n";
-
-  std::cout << fmt::format("therefore ratio lengthA / lengthB == {}\n\n", lengthA / lengthB);
-
-  std::cout << fmt::format("conversion factor from lengthA::unit of {:%q} to lengthB::unit of {:%q}:\n\n", lengthA, lengthB)
-            << fmt::format("lengthB.number( {} ) == lengthA.number( {} ) * conversion_factor( {} )\n",
-                           lengthB.number(), lengthA.number(), conversion_factor(lengthB, lengthA));
-}