Merge branch 'master' of github.com:mpusz/mp-units

example/currency.cpp

@@ -63,7 +63,7 @@ inline constexpr auto JPY = japanese_jen;
 static_assert(!std::equality_comparable_with<quantity<euro, int>, quantity<us_dollar, int>>);
 
 
-#if 0  // NOLINT(readability-avoid-unconditional-preprocessor-if)
+#if 0 || !MP_UNITS_API_STRING_VIEW_RET  // NOLINT(readability-avoid-unconditional-preprocessor-if)
 
 // if you have only a few currencies to handle
 template<Unit auto From, Unit auto To>
@@ -77,8 +77,6 @@ template<Unit auto From, Unit auto To>
 
 #else
 
-[[nodiscard]] std::string_view to_string_view(Unit auto u) { return u.symbol.portable().c_str(); }
-
 template<Unit auto From, Unit auto To>
 [[nodiscard]] double exchange_rate(std::chrono::sys_seconds timestamp)
 {
@@ -88,7 +86,7 @@ template<Unit auto From, Unit auto To>
     // ...
   };
 
-  return rates.at(std::make_pair(to_string_view(From), to_string_view(To)));
+  return rates.at(std::make_pair(unit_symbol(From), unit_symbol(To)));
 }
 
 #endif

src/core/include/mp-units/bits/get_associated_quantity.h

@@ -51,10 +51,10 @@ template<typename... Nums, typename... Dens>
 template<AssociatedUnit U>
 [[nodiscard]] consteval auto all_are_kinds(U)
 {
-  if constexpr (requires { U::quantity_spec; })
-    return QuantityKindSpec<std::remove_const_t<decltype(U::quantity_spec)>>;
-  else if constexpr (requires { U::reference_unit; })
-    return all_are_kinds(U::reference_unit);
+  if constexpr (requires { U::_quantity_spec_; })
+    return QuantityKindSpec<std::remove_const_t<decltype(U::_quantity_spec_)>>;
+  else if constexpr (requires { U::_reference_unit_; })
+    return all_are_kinds(U::_reference_unit_);
   else if constexpr (requires { typename U::_num_; }) {
     return all_are_kinds(typename U::_num_{}, typename U::_den_{});
   }
@@ -75,10 +75,10 @@ template<typename... Us>
 template<AssociatedUnit U>
 [[nodiscard]] consteval auto get_associated_quantity_impl(U u)
 {
-  if constexpr (requires { U::quantity_spec; })
-    return remove_kind(U::quantity_spec);
-  else if constexpr (requires { U::reference_unit; })
-    return get_associated_quantity_impl(U::reference_unit);
+  if constexpr (requires { U::_quantity_spec_; })
+    return remove_kind(U::_quantity_spec_);
+  else if constexpr (requires { U::_reference_unit_; })
+    return get_associated_quantity_impl(U::_reference_unit_);
   else if constexpr (requires { typename U::_num_; }) {
     return expr_map<to_quantity_spec, derived_quantity_spec, struct dimensionless, type_list_of_quantity_spec_less>(u);
   }

src/core/include/mp-units/framework/dimension.h

@@ -120,7 +120,7 @@ struct dimension_interface {
  */
 MP_UNITS_EXPORT template<symbol_text Symbol>
 struct base_dimension : detail::dimension_interface {
-  static constexpr auto symbol = Symbol;  ///< Unique base dimension identifier
+  static constexpr auto _symbol_ = Symbol;  ///< Unique base dimension identifier
 };
 
 /**
@@ -229,10 +229,10 @@ MP_UNITS_EXPORT_END
 namespace detail {
 
 template<typename CharT, std::output_iterator<CharT> Out, Dimension D>
-  requires requires { D::symbol; }
+  requires requires { D::_symbol_; }
 constexpr Out dimension_symbol_impl(Out out, D, const dimension_symbol_formatting& fmt, bool negative_power)
 {
-  return copy_symbol<CharT>(D::symbol, fmt.encoding, negative_power, out);
+  return copy_symbol<CharT>(D::_symbol_, fmt.encoding, negative_power, out);
 }
 
 template<typename CharT, std::output_iterator<CharT> Out, typename F, int Num, int... Den>

src/core/include/mp-units/framework/quantity.h

@@ -112,8 +112,8 @@ concept SameValueAs = (equivalent(get_unit(R1), get_unit(R2))) && std::convertib
 template<typename T>
 using quantity_like_type = quantity<quantity_like_traits<T>::reference, typename quantity_like_traits<T>::rep>;
 
-template<typename T, typename U>
-concept Forwarding = std::derived_from<std::remove_cvref_t<T>, U>;
+template<typename T, typename U, typename TT = std::remove_reference_t<T>>
+concept Mutable = (!std::is_const_v<TT>) && std::derived_from<TT, U>;
 
 }  // namespace detail
 
@@ -338,7 +338,7 @@ class quantity {
     return ::mp_units::quantity{-numerical_value_is_an_implementation_detail_, reference};
   }
 
-  template<detail::Forwarding<quantity> Q>
+  template<detail::Mutable<quantity> Q>
   friend constexpr decltype(auto) operator++(Q&& q)
     requires requires(rep v) {
       { ++v } -> std::same_as<rep&>;
@@ -356,7 +356,7 @@ class quantity {
     return ::mp_units::quantity{numerical_value_is_an_implementation_detail_++, reference};
   }
 
-  template<detail::Forwarding<quantity> Q>
+  template<detail::Mutable<quantity> Q>
   friend constexpr decltype(auto) operator--(Q&& q)
     requires requires(rep v) {
       { --v } -> std::same_as<rep&>;
@@ -375,7 +375,7 @@ class quantity {
   }
 
   // compound assignment operators
-  template<detail::Forwarding<quantity> Q, auto R2, typename Rep2>
+  template<detail::Mutable<quantity> Q, auto R2, typename Rep2>
     requires detail::QuantityConvertibleTo<quantity<R2, Rep2>, quantity> && requires(rep a, Rep2 b) {
       { a += b } -> std::same_as<rep&>;
     }
@@ -388,7 +388,7 @@ class quantity {
     return std::forward<Q>(lhs);
   }
 
-  template<detail::Forwarding<quantity> Q, auto R2, typename Rep2>
+  template<detail::Mutable<quantity> Q, auto R2, typename Rep2>
     requires detail::QuantityConvertibleTo<quantity<R2, Rep2>, quantity> && requires(rep a, Rep2 b) {
       { a -= b } -> std::same_as<rep&>;
     }
@@ -401,7 +401,7 @@ class quantity {
     return std::forward<Q>(lhs);
   }
 
-  template<detail::Forwarding<quantity> Q, auto R2, typename Rep2>
+  template<detail::Mutable<quantity> Q, auto R2, typename Rep2>
     requires detail::QuantityConvertibleTo<quantity<R2, Rep2>, quantity> && (!treat_as_floating_point<rep>) &&
              requires(rep a, Rep2 b) {
                { a %= b } -> std::same_as<rep&>;
@@ -417,7 +417,7 @@ class quantity {
     return std::forward<Q>(lhs);
   }
 
-  template<detail::Forwarding<quantity> Q, detail::ValuePreservingTo<Rep> Value>
+  template<detail::Mutable<quantity> Q, detail::ValuePreservingTo<Rep> Value>
     requires(!Quantity<Value>) && requires(rep a, Value b) {
       { a *= b } -> std::same_as<rep&>;
     }
@@ -429,7 +429,7 @@ class quantity {
     return std::forward<Q>(lhs);
   }
 
-  template<detail::Forwarding<quantity> Q1, QuantityOf<dimensionless> Q2>
+  template<detail::Mutable<quantity> Q1, QuantityOf<dimensionless> Q2>
     requires(Q2::unit == ::mp_units::one) && detail::ValuePreservingTo<typename Q2::rep, Rep> &&
             requires(rep a, Q2::rep b) {
               { a *= b } -> std::same_as<rep&>;
@@ -439,7 +439,7 @@ class quantity {
     return std::forward<Q1>(lhs) *= rhs.numerical_value_is_an_implementation_detail_;
   }
 
-  template<detail::Forwarding<quantity> Q, detail::ValuePreservingTo<Rep> Value>
+  template<detail::Mutable<quantity> Q, detail::ValuePreservingTo<Rep> Value>
     requires(!Quantity<Value>) && requires(rep a, Value b) {
       { a /= b } -> std::same_as<rep&>;
     }
@@ -452,7 +452,7 @@ class quantity {
     return std::forward<Q>(lhs);
   }
 
-  template<detail::Forwarding<quantity> Q1, QuantityOf<dimensionless> Q2>
+  template<detail::Mutable<quantity> Q1, QuantityOf<dimensionless> Q2>
     requires(Q2::unit == ::mp_units::one) && detail::ValuePreservingTo<typename Q2::rep, Rep> &&
             requires(rep a, Q2::rep b) {
               { a /= b } -> std::same_as<rep&>;

src/core/include/mp-units/framework/quantity_concepts.h

@@ -59,8 +59,10 @@ template<typename T, template<typename> typename Traits>
 concept QuantityLikeImpl = requires(const T& qty, const Traits<T>::rep& num) {
   { Traits<T>::to_numerical_value(qty) } -> std::same_as<typename Traits<T>::rep>;
   { Traits<T>::from_numerical_value(num) } -> std::same_as<T>;
-  { Traits<T>::explicit_import } -> std::convertible_to<bool>;
-  { Traits<T>::explicit_export } -> std::convertible_to<bool>;
+  requires std::same_as<decltype(Traits<T>::explicit_import), const bool>;
+  requires std::same_as<decltype(Traits<T>::explicit_export), const bool>;
+  typename std::bool_constant<Traits<T>::explicit_import>;
+  typename std::bool_constant<Traits<T>::explicit_export>;
 };
 
 }  // namespace detail