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QPair: use std::type_traits for exception specifications

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This should solve problems with our use of the noexcept
operator, because that's how std::pair is defined, too.

Mid-term, we should kill QPair and use std::pair instead.
It really has gotten way too complicated to implement a
C++11 pair correctly.

Task-number: QTBUG-48780
Change-Id: Ied0acd220e5131000a957dc356d6efcdd8f83828
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>
This commit is contained in:
Marc Mutz 2015-11-06 11:21:19 +01:00
parent dfc76d57b2
commit 226ce6020e
1 changed files with 12 additions and 6 deletions
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18
src/corelib/tools/qpair.h
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@ -46,30 +46,36 @@ struct QPair
typedef T2 second_type;
Q_DECL_CONSTEXPR QPair()
Q_DECL_NOEXCEPT_EXPR(noexcept(T1()) && noexcept(T2()))
Q_DECL_NOEXCEPT_EXPR((std::is_nothrow_default_constructible<T1>::value &&
std::is_nothrow_default_constructible<T2>::value))
: first(), second() {}
Q_DECL_CONSTEXPR QPair(const T1 &t1, const T2 &t2)
Q_DECL_NOEXCEPT_EXPR(noexcept(T1(t1)) && noexcept(T2(t2)))
Q_DECL_NOEXCEPT_EXPR((std::is_nothrow_copy_constructible<T1>::value &&
std::is_nothrow_copy_constructible<T2>::value))
: first(t1), second(t2) {}
// compiler-generated copy/move ctor/assignment operators are fine!
template <typename TT1, typename TT2>
Q_DECL_CONSTEXPR QPair(const QPair<TT1, TT2> &p)
Q_DECL_NOEXCEPT_EXPR(noexcept(T1(p.first)) && noexcept(T2(p.second)))
Q_DECL_NOEXCEPT_EXPR((std::is_nothrow_constructible<T1, TT1&>::value &&
std::is_nothrow_constructible<T2, TT2&>::value))
: first(p.first), second(p.second) {}
template <typename TT1, typename TT2>
Q_DECL_RELAXED_CONSTEXPR QPair &operator=(const QPair<TT1, TT2> &p)
Q_DECL_NOEXCEPT_EXPR(noexcept(std::declval<T1&>() = p.first) && noexcept(std::declval<T2&>() = p.second))
Q_DECL_NOEXCEPT_EXPR((std::is_nothrow_assignable<T1, TT1&>::value &&
std::is_nothrow_assignable<T2, TT2&>::value))
{ first = p.first; second = p.second; return *this; }
#ifdef Q_COMPILER_RVALUE_REFS
template <typename TT1, typename TT2>
Q_DECL_CONSTEXPR QPair(QPair<TT1, TT2> &&p)
Q_DECL_NOEXCEPT_EXPR((std::is_nothrow_constructible<T1, TT1>::value &&
std::is_nothrow_constructible<T2, TT2>::value))
// can't use std::move here as it's not constexpr in C++11:
Q_DECL_NOEXCEPT_EXPR(noexcept(T1(static_cast<TT1 &&>(p.first))) && noexcept(T2(static_cast<TT2 &&>(p.second))))
: first(static_cast<TT1 &&>(p.first)), second(static_cast<TT2 &&>(p.second)) {}
template <typename TT1, typename TT2>
Q_DECL_RELAXED_CONSTEXPR QPair &operator=(QPair<TT1, TT2> &&p)
Q_DECL_NOEXCEPT_EXPR(noexcept(std::declval<T1&>() = std::move(p.first)) && noexcept(std::declval<T2&>() = std::move(p.second)))
Q_DECL_NOEXCEPT_EXPR((std::is_nothrow_assignable<T1, TT1>::value &&
std::is_nothrow_assignable<T2, TT2>::value))
{ first = std::move(p.first); second = std::move(p.second); return *this; }
#endif