[hash] Add hash impl for integers

Part of https://github.com/harfbuzz/harfbuzz/issues/4227
2 years ago · 0e02680803
parent b7a8d23bc8
commit 0e02680803
1 changed files with 5 additions and 1 deletions
--- a/src/hb-algs.hh
+++ b/src/hb-algs.hh
@ -236,7 +236,11 @@ struct
  private:

  template <typename T> constexpr auto
-  impl (const T& v, hb_priority<1>) const HB_RETURN (uint32_t, hb_deref (v).hash ())
+  impl (const T& v, hb_priority<2>) const HB_RETURN (uint32_t, hb_deref (v).hash ())
+
+  // Horrible: std:hash() of integers seems to be identity in gcc / clang?!
+  template <typename T> constexpr auto
+  impl (const T& v, hb_priority<1>) const HB_RETURN (uint32_t, v * 2654435761u)

  template <typename T> constexpr auto
  impl (const T& v, hb_priority<0>) const HB_RETURN (uint32_t, std::hash<hb_decay<decltype (hb_deref (v))>>{} (hb_deref (v)))