diff options
| author | Ulf Hermann <ulf.hermann@qt.io> | 2020-12-01 11:54:43 +0100 |
|---|---|---|
| committer | Ulf Hermann <ulf.hermann@qt.io> | 2020-12-07 15:37:25 +0100 |
| commit | 2b8674a2fc67089ff87d3751ef2977cbb37616a2 (patch) | |
| tree | c767cf155ab1f8acee28c3aeb40ea82701afe65d /src/corelib/global/qnumeric.cpp | |
| parent | 9082cc8e8d5a6441dabe5e7a95bc0cd9085b95fe (diff) | |
Make the overflow math functions public
As the standard library does not provide equivalent functionality, those
functions are really useful to everyone, not only to Qt itself.
[ChangeLog][QtCore] The overflow-safe math functions qAddOverflow(),
qSubOverflow(), qMulOverflow() were added.
Change-Id: I5a0a4742dae9b6f0caa65d0e93edcf3658bee9f8
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Diffstat (limited to 'src/corelib/global/qnumeric.cpp')
| -rw-r--r-- | src/corelib/global/qnumeric.cpp | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/src/corelib/global/qnumeric.cpp b/src/corelib/global/qnumeric.cpp index e00f0af283e..63055a0b61c 100644 --- a/src/corelib/global/qnumeric.cpp +++ b/src/corelib/global/qnumeric.cpp @@ -254,5 +254,99 @@ Q_CORE_EXPORT quint64 qFloatDistance(double a, double b) return a > b ? d2i(a) - d2i(b) : d2i(b) - d2i(a); } +/*! + \fn template<typename T> bool qAddOverflow(T v1, T v2, T *result) + \since 6.1 + + Adds two values \a v1 and \a v2, of a numeric type \c T and records the + value in \a result. If the addition overflows the valid range for type \c T, + returns \c true, otherwise returns \c false. + + An implementation is guaranteed to be available for 8-, 16-, and 32-bit + integer types, as well as integer types of the size of a pointer. Overflow + math for other types, if available, is considered private API. +*/ + +/*! + \fn template <typename T, T V2> bool qAddOverflow(T v1, std::integral_constant<T, V2>, T *r) + \since 6.1 + \internal + + Equivalent to qAddOverflow(v1, v2, r) with \a v1 as first argument, the + compile time constant \c V2 as second argument, and \a r as third argument. +*/ + +/*! + \fn template <auto V2, typename T> bool qAddOverflow(T v1, T *r) + \since 6.1 + \internal + + Equivalent to qAddOverflow(v1, v2, r) with \a v1 as first argument, the + compile time constant \c V2 as second argument, and \a r as third argument. +*/ + +/*! + \fn template<typename T> bool qSubOverflow(T v1, T v2, T *result) + \since 6.1 + + Subtracts \a v2 from \a v1 and records the resulting value in \a result. If + the subtraction overflows the valid range for type \c T, returns \c true, + otherwise returns \c false. + + An implementation is guaranteed to be available for 8-, 16-, and 32-bit + integer types, as well as integer types of the size of a pointer. Overflow + math for other types, if available, is considered private API. +*/ + +/*! + \fn template <typename T, T V2> bool qSubOverflow(T v1, std::integral_constant<T, V2>, T *r) + \since 6.1 + \internal + + Equivalent to qSubOverflow(v1, v2, r) with \a v1 as first argument, the + compile time constant \c V2 as second argument, and \a r as third argument. +*/ + +/*! + \fn template <auto V2, typename T> bool qSubOverflow(T v1, T *r) + \since 6.1 + \internal + + Equivalent to qSubOverflow(v1, v2, r) with \a v1 as first argument, the + compile time constant \c V2 as second argument, and \a r as third argument. +*/ + +/*! + \fn template<typename T> bool qMulOverflow(T v1, T v2, T *result) + \since 6.1 + + Multiplies \a v1 and \a v2, and records the resulting value in \a result. If + the multiplication overflows the valid range for type \c T, returns + \c true, otherwise returns \c false. + + An implementation is guaranteed to be available for 8-, 16-, and 32-bit + integer types, as well as integer types of the size of a pointer. Overflow + math for other types, if available, is considered private API. +*/ + +/*! + \fn template <typename T, T V2> bool qMulOverflow(T v1, std::integral_constant<T, V2>, T *r) + \since 6.1 + \internal + + Equivalent to qMulOverflow(v1, v2, r) with \a v1 as first argument, the + compile time constant \c V2 as second argument, and \a r as third argument. + This can be faster than calling the version with only variable arguments. +*/ + +/*! + \fn template <auto V2, typename T> bool qMulOverflow(T v1, T *r) + \since 6.1 + \internal + + Equivalent to qMulOverflow(v1, v2, r) with \a v1 as first argument, the + compile time constant \c V2 as second argument, and \a r as third argument. + This can be faster than calling the version with only variable arguments. +*/ QT_END_NAMESPACE |