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Directly cast to size_t all integrals no wider than size_t

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This commit is contained in:
Peter Dimov
2022-06-26 01:25:45 +03:00
parent e39bf42dfc
commit c28d0b813b
1 changed files with 23 additions and 21 deletions
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44
include/boost/container_hash/hash.hpp
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@@ -77,11 +77,12 @@ namespace boost
{ {
template<class T, template<class T,
bool bigger_than_size_t = (sizeof(T) > sizeof(std::size_t)), bool bigger_than_size_t = (sizeof(T) > sizeof(std::size_t)),
bool is_unsigned = boost::is_unsigned<T>::value,
std::size_t size_t_bits = sizeof(std::size_t) * CHAR_BIT, std::size_t size_t_bits = sizeof(std::size_t) * CHAR_BIT,
std::size_t type_bits = sizeof(T) * CHAR_BIT> std::size_t type_bits = sizeof(T) * CHAR_BIT>
struct hash_integral_impl; struct hash_integral_impl;
template<class T, std::size_t size_t_bits, std::size_t type_bits> struct hash_integral_impl<T, false, size_t_bits, type_bits> template<class T, bool is_unsigned, std::size_t size_t_bits, std::size_t type_bits> struct hash_integral_impl<T, false, is_unsigned, size_t_bits, type_bits>
{ {
static std::size_t fn( T v ) static std::size_t fn( T v )
{ {
@@ -89,7 +90,24 @@ namespace boost
} }
}; };
template<class T> struct hash_integral_impl<T, true, 32, 64> template<class T, std::size_t size_t_bits, std::size_t type_bits> struct hash_integral_impl<T, true, false, size_t_bits, type_bits>
{
static std::size_t fn( T v )
{
typedef typename boost::make_unsigned<T>::type U;
if( v >= 0 )
{
return hash_integral_impl<U>::fn( static_cast<U>( v ) );
}
else
{
return ~hash_integral_impl<U>::fn( static_cast<U>( ~static_cast<U>( v ) ) );
}
}
};
template<class T> struct hash_integral_impl<T, true, true, 32, 64>
{ {
static std::size_t fn( T v ) static std::size_t fn( T v )
{ {
@@ -102,7 +120,7 @@ namespace boost
} }
}; };
template<class T> struct hash_integral_impl<T, true, 32, 128> template<class T> struct hash_integral_impl<T, true, true, 32, 128>
{ {
static std::size_t fn( T v ) static std::size_t fn( T v )
{ {
@@ -117,7 +135,7 @@ namespace boost
} }
}; };
template<class T> struct hash_integral_impl<T, true, 64, 128> template<class T> struct hash_integral_impl<T, true, true, 64, 128>
{ {
static std::size_t fn( T v ) static std::size_t fn( T v )
{ {
@@ -133,28 +151,12 @@ namespace boost
} // namespace hash_detail } // namespace hash_detail
template <typename T> template <typename T>
typename boost::enable_if_<boost::conjunction<boost::is_integral<T>, boost::is_unsigned<T> >::value, std::size_t>::type typename boost::enable_if_<boost::is_integral<T>::value, std::size_t>::type
hash_value( T v ) hash_value( T v )
{ {
return hash_detail::hash_integral_impl<T>::fn( v ); return hash_detail::hash_integral_impl<T>::fn( v );
} }
template <typename T>
typename boost::enable_if_<boost::conjunction<boost::is_integral<T>, boost::is_signed<T> >::value, std::size_t>::type
hash_value( T v )
{
typedef typename boost::make_unsigned<T>::type U;
if( v >= 0 )
{
return hash_value( static_cast<U>( v ) );
}
else
{
return ~hash_value( static_cast<U>( ~static_cast<U>( v ) ) );
}
}
// enumeration types // enumeration types
template <typename T> template <typename T>