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author | Marc Mutz <marc.mutz@kdab.com> | 2014-02-12 14:18:40 +0100 |
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committer | The Qt Project <gerrit-noreply@qt-project.org> | 2014-02-16 00:18:32 +0100 |
commit | c0791ac76ec7cfdc3945efa67a6f72ee3623413c (patch) | |
tree | 341d42284f1c50dfc7235baecbbd828e765a8b2a /src/corelib/tools/qlocale_p.h | |
parent | d24cceebf2bad8e1172cf992644263cba2098501 (diff) |
Add qHash() overloads for floating-point types
This implementation is based on GCC's implementation of std::hash<FP>, but only
to the extent of checking for zero before hashing the bits. The bit hasher is
the Qt one; I didn't even look what GCC uses.
The check against 0.0 is mandated by the requirement to have
\forall x,y: x == y => qHash(x) == qHash(y)
which would be violated for x = 0.0 and y = -0.0 if we only hashed the bits.
Implemented out-of-line to avoid potential FP-comparison warnings, as well
as to be able to use the file-static hash() functions, which gets inlined
unlike qHashBits(), which cannot be.
[ChangeLog][QtCore][QHash/QSet] Allowed to use float, double and long double
as QHash/QSet keys.
Change-Id: I38cec4afb860f17e9f8be7b67544e58b330f8fff
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>
Diffstat (limited to 'src/corelib/tools/qlocale_p.h')
0 files changed, 0 insertions, 0 deletions