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| author | Pieter Wuille <pieter@wuille.net> | 2020-06-18 16:31:08 -0700 |
|---|---|---|
| committer | Pieter Wuille <pieter@wuille.net> | 2020-07-30 13:57:09 -0700 |
| commit | e63dcc3a6752e7d406e7a650c2d6c2e95cd39aab (patch) | |
| tree | b34c1f56300dcb2a9248610a443d7311a5e5cc27 /src/span.h | |
| parent | 567825049fb0e47e698dcaad9caa65693a6b42d3 (diff) | |
| download | bitcoin-e63dcc3a6752e7d406e7a650c2d6c2e95cd39aab.tar.xz | |
Add MakeUCharSpan, to help constructing Span<[const] unsigned char>
Based on a suggestion by Russell Yanofsky.
Diffstat (limited to 'src/span.h')
| -rw-r--r-- | src/span.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/src/span.h b/src/span.h index 79f13c9203..4afb383a59 100644 --- a/src/span.h +++ b/src/span.h @@ -207,4 +207,16 @@ T& SpanPopBack(Span<T>& span) return back; } +// Helper functions to safely cast to unsigned char pointers. +inline unsigned char* UCharCast(char* c) { return (unsigned char*)c; } +inline unsigned char* UCharCast(unsigned char* c) { return c; } +inline const unsigned char* UCharCast(const char* c) { return (unsigned char*)c; } +inline const unsigned char* UCharCast(const unsigned char* c) { return c; } + +// Helper function to safely convert a Span to a Span<[const] unsigned char>. +template <typename T> constexpr auto UCharSpanCast(Span<T> s) -> Span<typename std::remove_pointer<decltype(UCharCast(s.data()))>::type> { return {UCharCast(s.data()), s.size()}; } + +/** Like MakeSpan, but for (const) unsigned char member types only. Only works for (un)signed char containers. */ +template <typename V> constexpr auto MakeUCharSpan(V&& v) -> decltype(UCharSpanCast(MakeSpan(std::forward<V>(v)))) { return UCharSpanCast(MakeSpan(std::forward<V>(v))); } + #endif |