comparison: src/typeconversions.h
src/typeconversions.h
- changeset 218
- 63125c36de73
- child 250
- 2837b549e616
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| 217:6d95c1a41e6e | 218:63125c36de73 |
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| 1 #ifndef TYPECONVERSIONS_H | |
| 2 #define TYPECONVERSIONS_H | |
| 3 #include <type_traits> | |
| 4 #include <QtGlobal> | |
| 5 | |
| 6 template<typename T, typename R> | |
| 7 struct transfer_cvref | |
| 8 { | |
| 9 using type = std::remove_reference_t<R>; | |
| 10 }; | |
| 11 | |
| 12 template<typename T, typename R> | |
| 13 struct transfer_cvref<T&, R> | |
| 14 { | |
| 15 using type = std::remove_reference_t<R>&; | |
| 16 }; | |
| 17 | |
| 18 template<typename T, typename R> | |
| 19 struct transfer_cvref<const T&, R> | |
| 20 { | |
| 21 using type = const std::remove_reference_t<R>&; | |
| 22 }; | |
| 23 | |
| 24 template<typename T, typename R> | |
| 25 struct transfer_cvref<T&&, R> | |
| 26 { | |
| 27 using type = std::remove_reference_t<R>&&; | |
| 28 }; | |
| 29 | |
| 30 //! \brief transfer l-value reference, r-value reference and const l-value | |
| 31 //! reference from T onto R | |
| 32 template<typename T, typename R> | |
| 33 using transfer_cvref_t = typename transfer_cvref<T, R>::type; | |
| 34 static_assert(std::is_same_v<transfer_cvref_t<int, char>, char>); | |
| 35 static_assert(std::is_same_v<transfer_cvref_t<int&, char>, char&>); | |
| 36 static_assert(std::is_same_v<transfer_cvref_t<int&&, char>, char&&>); | |
| 37 | |
| 38 //! \brief casts @c x to a suitable unsigned integer | |
| 39 template<typename T> | |
| 40 constexpr auto unsigned_cast(T x) | |
| 41 -> std::enable_if_t<std::is_integral_v<T>, std::make_unsigned_t<T>> | |
| 42 { | |
| 43 return static_cast<std::make_unsigned_t<T>>(x); | |
| 44 } | |
| 45 | |
| 46 //! \brief casts @c x to a suitable signed integer | |
| 47 template<typename T> | |
| 48 constexpr auto signed_cast(T x) | |
| 49 -> std::enable_if_t<std::is_integral_v<T>, std::make_signed_t<T>> | |
| 50 { | |
| 51 return static_cast<std::make_signed_t<T>>(x); | |
| 52 } | |
| 53 | |
| 54 //! \brief casts floating point values to float | |
| 55 template<typename T> | |
| 56 constexpr auto float_cast(T x) | |
| 57 -> std::enable_if_t<std::is_floating_point_v<T>, float> | |
| 58 { | |
| 59 return static_cast<float>(x); | |
| 60 } | |
| 61 | |
| 62 //! \brief casts floating point values to double | |
| 63 template<typename T> | |
| 64 constexpr auto double_cast(T x) | |
| 65 -> std::enable_if_t<std::is_floating_point_v<T>, double> | |
| 66 { | |
| 67 return static_cast<double>(x); | |
| 68 } | |
| 69 | |
| 70 //! \brief casts floating point values to qreal | |
| 71 template<typename T> | |
| 72 constexpr auto qreal_cast(T x) | |
| 73 -> std::enable_if_t<std::is_floating_point_v<T>, qreal> | |
| 74 { | |
| 75 return static_cast<qreal>(x); | |
| 76 } | |
| 77 | |
| 78 //! \brief convert an enum value to its corresponding integer value (including | |
| 79 //! references) | |
| 80 template<typename T> | |
| 81 constexpr auto&& enum_value_cast(T&& enu) | |
| 82 { | |
| 83 using valuetype = std::underlying_type_t<std::remove_cvref_t<T>>; | |
| 84 using reftype = transfer_cvref_t<T&&, valuetype>; | |
| 85 return reinterpret_cast<reftype>(enu); | |
| 86 } | |
| 87 | |
| 88 #endif // TYPECONVERSIONS_H |
