fix(strutil.h): ensure proper constexpr of string hashing #3901
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@AlexMWells, can you confirm if this totally fixes your problem? |
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Yes it does fix the issue and allow global constexpr variables and consteval expressions. Thanks for adding a test by the way. |
The underlying farmhash algorithm (which is the basis for Strutil::strhash, and thus ustring's hash representation) turned out to not be properly constexpr under certain circumstances and needed to be expressed a different way to be fully constexpr on all platforms and for all strings. New implementation suggested by Alex Wells. Also, make sure string_view ctr from char* can be constexpr, even for C++14. This is related for the sake of the strhash calls that, when taking string literals, actually choose the variety that accepts a string_view. Signed-off-by: Larry Gritz <[email protected]>
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Updated: Also, make sure string_view ctr from char* can be constexpr, even for |
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…twareFoundation#3901) The underlying farmhash algorithm (which is the basis for Strutil::strhash, and thus ustring's hash representation) turned out to not be properly constexpr under certain circumstances and needed to be expressed a different way to be fully constexpr on all platforms and for all strings. New implementation suggested by Alex Wells. Also, make sure string_view ctr from char* can be constexpr, even for C++14. This is related for the sake of the strhash calls that, when taking string literals, actually choose the variety that accepts a string_view. Signed-off-by: Larry Gritz <[email protected]>
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The underlying farmhash algorithm (which is the basis for Strutil::strhash, and thus ustring's hash representation) turned out to not be properly constexpr under certain circumstances and needed to be expressed a different way to be fully constexpr on all platforms and for all strings.
New implementation suggested by Alex Wells.
Also, make sure string_view ctr from char* can be constexpr, even for
C++14. This is related for the sake of the strhash calls that, when
taking string literals, actually choose the variety that accepts a
string_view.