Maybe fix hashing strings

3rdparty/code_from_boost/hash/hash.hpp

@@ -41,6 +41,7 @@
 #include <vector>
 #include <cstdint>
 #include <climits>
+#include <numeric>
 #include <type_traits>
 
 namespace boost_hash
@@ -232,7 +233,12 @@ namespace boost_hash
  return w;
  }
 
- std::size_t hash_range( std::size_t seed, const char *first, const char *last )
+ template<class It>
+ inline typename std::enable_if<
+ std::is_same<char, typename std::remove_const<typename std::remove_pointer<It>::type >::type >::value
+ && (std::numeric_limits<std::size_t>::digits > 32),
+ std::size_t>::type
+ hash_range( std::size_t seed, It first, It last )
  {
  const char *p = first;
  std::size_t n = static_cast<std::size_t>( last - first );
@@ -278,6 +284,65 @@ namespace boost_hash
 
  return mulx( h + w, k );
  }
+
+ std::uint64_t mul32( std::uint32_t x, std::uint32_t y )
+ {
+ return static_cast<std::uint64_t>( x ) * y;
+ }
+
+ template<class It>
+ inline typename std::enable_if<
+ std::is_same<char, typename std::remove_const<typename std::remove_pointer<It>::type >::type >::value
+ && (std::numeric_limits<std::size_t>::digits <= 32),
+ std::size_t>::type
+ hash_range( std::size_t seed, It first, It last )
+ {
+ It p = first;
+ std::size_t n = static_cast<std::size_t>( last - first );
+
+ std::uint32_t const q = 0x9e3779b9U;
+ std::uint32_t const k = 0xe35e67b1U; // q * q
+
+ std::uint64_t h = mul32( static_cast<std::uint32_t>( seed ) + q, k );
+ std::uint32_t w = static_cast<std::uint32_t>( h & 0xFFFFFFFF );
+
+ h ^= n;
+
+ while( n >= 4 )
+ {
+ std::uint32_t v1 = read32le( p );
+
+ w += q;
+ h ^= mul32( v1 + w, k );
+
+ p += 4;
+ n -= 4;
+ }
+
+ {
+ std::uint32_t v1 = 0;
+
+ if( n >= 1 )
+ {
+ std::size_t const x1 = ( n - 1 ) & 2; // 1: 0, 2: 0, 3: 2
+ std::size_t const x2 = n >> 1; // 1: 0, 2: 1, 3: 1
+
+ v1 =
+ static_cast<std::uint32_t>( static_cast<unsigned char>( p[ static_cast<std::ptrdiff_t>( x1 ) ] ) ) << x1 * 8 |
+ static_cast<std::uint32_t>( static_cast<unsigned char>( p[ static_cast<std::ptrdiff_t>( x2 ) ] ) ) << x2 * 8 |
+ static_cast<std::uint32_t>( static_cast<unsigned char>( p[ 0 ] ) );
+ }
+
+ w += q;
+ h ^= mul32( v1 + w, k );
+ }
+
+ w += q;
+ h ^= mul32( static_cast<std::uint32_t>( h & 0xFFFFFFFF ) + w, static_cast<std::uint32_t>( h >> 32 ) + w + k );
+
+ return static_cast<std::uint32_t>( h & 0xFFFFFFFF ) ^ static_cast<std::uint32_t>( h >> 32 );
+ }
+
  }//namespace hash_detail
 
  // Hash floating point types (e.g., `float` and `double`)
@@ -298,7 +363,9 @@ namespace boost_hash
 
  std::size_t hash_value( const std::string &v )
  {
- return boost_hash::hash_detail::hash_range( 0, v.data(), v.data() + v.size() );
+ const char *start = v.data();
+ const char *end = v.data() + v.size();
+ return boost_hash::hash_detail::hash_range( size_t(0), start, end );
  }
 
  template <class T>