feat: value_cast support added

Resolves #239 and #120

example/avg_speed.cpp

@@ -52,8 +52,7 @@ constexpr QuantityOf<isq::speed> auto avg_speed(QuantityOf<isq::length> auto d,
 template<QuantityOf<isq::length> D, QuantityOf<isq::time> T, QuantityOf<isq::speed> V>
 void print_result(D distance, T duration, V speed)
 {
-  constexpr auto kmph = si::kilo<si::metre> / si::hour;
-  const auto result_in_kmph = quantity_cast<kmph>(speed);
+  const auto result_in_kmph = value_cast<km / h>(speed);
   std::cout << "Average speed of a car that makes " << distance << " in " << duration << " is " << result_in_kmph
             << ".\n";
 }
@@ -80,8 +79,7 @@ void example()
     std::cout << "\nSI units with 'double' as representation\n";
 
     // conversion from a floating-point to an integral type is a truncating one so an explicit cast is needed
-    print_result(distance, duration,
-                 fixed_int_si_avg_speed(quantity_cast<int>(distance), quantity_cast<int>(duration)));
+    print_result(distance, duration, fixed_int_si_avg_speed(value_cast<int>(distance), value_cast<int>(duration)));
     print_result(distance, duration, fixed_double_si_avg_speed(distance, duration));
     print_result(distance, duration, avg_speed(distance, duration));
   }
@@ -97,7 +95,7 @@ void example()
 
     // it is not possible to make a lossless conversion of miles to meters on an integral type
     // (explicit cast needed)
-    print_result(distance, duration, fixed_int_si_avg_speed(quantity_cast<si::metre>(distance), duration));
+    print_result(distance, duration, fixed_int_si_avg_speed(value_cast<si::metre>(distance), duration));
     print_result(distance, duration, fixed_double_si_avg_speed(distance, duration));
     print_result(distance, duration, avg_speed(distance, duration));
   }
@@ -114,9 +112,8 @@ void example()
     // conversion from a floating-point to an integral type is a truncating one so an explicit cast is needed
     // also it is not possible to make a lossless conversion of miles to meters on an integral type
     // (explicit cast needed)
-    print_result(
-      distance, duration,
-      fixed_int_si_avg_speed(quantity_cast<quantity<isq::length[m], int>>(distance), quantity_cast<int>(duration)));
+    print_result(distance, duration,
+                 fixed_int_si_avg_speed(value_cast<int>(value_cast<si::metre>(distance)), value_cast<int>(duration)));
     print_result(distance, duration, fixed_double_si_avg_speed(distance, duration));
     print_result(distance, duration, avg_speed(distance, duration));
   }
@@ -130,7 +127,7 @@ void example()
 
     // it is not possible to make a lossless conversion of centimeters to meters on an integral type
     // (explicit cast needed)
-    print_result(distance, duration, fixed_int_si_avg_speed(quantity_cast<si::metre>(distance), duration));
+    print_result(distance, duration, fixed_int_si_avg_speed(value_cast<si::metre>(distance), duration));
     print_result(distance, duration, fixed_double_si_avg_speed(distance, duration));
     print_result(distance, duration, avg_speed(distance, duration));
   }
@@ -145,9 +142,8 @@ void example()
     // conversion from a floating-point to an integral type is a truncating one so an explicit cast is needed
     // it is not possible to make a lossless conversion of centimeters to meters on an integral type
     // (explicit cast needed)
-    print_result(
-      distance, duration,
-      fixed_int_si_avg_speed(quantity_cast<quantity<isq::length[m], int>>(distance), quantity_cast<int>(duration)));
+    print_result(distance, duration,
+                 fixed_int_si_avg_speed(value_cast<int>(value_cast<m>(distance)), value_cast<int>(duration)));
 
     print_result(distance, duration, fixed_double_si_avg_speed(distance, duration));
     print_result(distance, duration, avg_speed(distance, duration));

example/capacitor_time_curve.cpp

@@ -40,7 +40,7 @@ int main()
   constexpr auto R = isq::resistance(4.7, si::kilo<si::ohm>);
 
   for (auto t = isq::time(0, ms); t <= isq::time(50, ms); ++t) {
-    const weak_quantity_of<isq::voltage> auto Vt = V0 * mp_units::exp(-t / (R * C));
+    const WeakQuantityOf<isq::voltage> auto Vt = V0 * mp_units::exp(-t / (R * C));
 
     std::cout << "at " << t << " voltage is ";
 

example/conversion_factor.cpp

@@ -32,7 +32,7 @@ template<mp_units::Quantity Target, mp_units::Quantity Source>
   requires std::constructible_from<Target, Source>
 inline constexpr double conversion_factor(Target, Source)
 {
-  return quantity_cast<Target::unit>(1. * Source::reference).number();
+  return value_cast<Target::unit>(1. * Source::reference).number();
 }
 
 }  // namespace

example/foot_pound_second.cpp

@@ -52,7 +52,7 @@ struct Ship {
 template<Unit auto... Us, Quantity Q>
 auto fmt_line(const Q& q)
 {
-  return STD_FMT::format("{:22}", q) + (STD_FMT::format(",{:20}", quantity_cast<Us>(q)) + ...);
+  return STD_FMT::format("{:22}", q) + (STD_FMT::format(",{:20}", value_cast<Us>(q)) + ...);
 }
 
 // Print the ship details in the units as defined in the Ship struct, in other si::imperial units, and in SI

example/glide_computer/glide_computer.cpp

@@ -77,7 +77,7 @@ void print(std::string_view phase_name, timestamp start_ts, const glide_computer
   std::cout << STD_FMT::format(
     "| {:<12} | {:>9%.1Q %q} (Total: {:>9%.1Q %q}) | {:>8%.1Q %q} (Total: {:>8%.1Q %q}) | {:>7%.0Q %q} ({:>6%.0Q %q}) "
     "|\n",
-    phase_name, quantity_cast<si::minute>(new_point.ts - point.ts), quantity_cast<si::minute>(new_point.ts - start_ts),
+    phase_name, value_cast<si::minute>(new_point.ts - point.ts), value_cast<si::minute>(new_point.ts - start_ts),
     new_point.dist - point.dist, new_point.dist, new_point.alt - point.alt, new_point.alt);
 }
 

example/glide_computer_example.cpp

@@ -85,11 +85,11 @@ void print(const R& gliders)
     std::cout << "- Name: " << g.name << "\n";
     std::cout << "- Polar:\n";
     for (const auto& p : g.polar) {
-      const auto ratio = quantity_cast<one>(glide_ratio(g.polar[0]));
+      const auto ratio = value_cast<one>(glide_ratio(g.polar[0]));
       std::cout << STD_FMT::format("  * {:%.4Q %q} @ {:%.1Q %q} -> {:%.1Q %q} ({:%.1Q %q})\n", p.climb, p.v, ratio,
                                    // TODO is it possible to make ADL work below (we need another set of trig functions
                                    // for strong angle in a different namespace)
-                                   quantity_cast<si::degree>(isq::asin(1 / ratio)));
+                                   value_cast<si::degree>(isq::asin(1 / ratio)));
     }
     std::cout << "\n";
   }

example/hello_units.cpp

@@ -43,9 +43,9 @@ int main()
   constexpr auto v2 = isq::speed(70., mph);
   constexpr auto v3 = avg_speed(isq::distance(220, km), isq::duration(2, h));
   constexpr auto v4 = avg_speed(quantity<isq::distance[mi]>{140}, quantity<isq::duration[h]>{2});
-  constexpr auto v5 = quantity_cast<quantity<isq::speed[m / s]>>(v3);
-  constexpr auto v6 = quantity_cast<m / s>(v4);
-  constexpr auto v7 = quantity_cast<int>(v6);
+  constexpr auto v5 = value_cast<m / s>(v3);
+  constexpr auto v6 = value_cast<m / s>(v4);
+  constexpr auto v7 = value_cast<int>(v6);
 
   std::cout << v1 << '\n';                                       // 110 km/h
   std::cout << v2 << '\n';                                       // 70 mi/h

example/linear_algebra.cpp

@@ -95,7 +95,7 @@ void quantity_of_vector_cast()
   std::cout << "v = " << v << "\n";
   std::cout << "u = " << u << "\n";
 
-  std::cout << "v[km] = " << quantity_cast<km>(v) << "\n";
+  std::cout << "v[km] = " << value_cast<km>(v) << "\n";
   std::cout << "u[m]  = " << u[m] << "\n";
 }
 

example/total_energy.cpp

@@ -80,7 +80,7 @@ void si_example()
             << "E = " << E3 << "\n";
 
   std::cout << "\n[converted from SI units back to GeV]\n"
-            << "E = " << quantity_cast<GeV>(E3) << "\n";
+            << "E = " << value_cast<GeV>(E3) << "\n";
 }
 
 void natural_example()