[libcxx] Properly convert the count arguments to the *_n algorithms before use.
Summary:
The requirement on the `Size` type passed to *_n algorithms is that it is convertible to an integral type. This means we can't use a variable of type `Size` directly. Instead we need to convert it to an integral type first. The problem is finding out what integral type to convert it to. `__convert_to_integral` figures out what integral type to convert it to and performs the conversion, It also promotes the resulting integral type so that it is at least as big as an integer. `__convert_to_integral` also has a special case for converting enums. This should only work on non-scoped enumerations because it does not apply an explicit conversion from the enum to its underlying type.
Reviewers: chandlerc, mclow.lists
Reviewed By: mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D7449
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@228704 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/algorithm b/include/algorithm
index 68173f4..475ba66 100644
--- a/include/algorithm
+++ b/include/algorithm
@@ -1672,7 +1672,8 @@
_Size __count, const _Tp& __value_, _BinaryPredicate __pred)
{
return _VSTD::__search_n<typename add_lvalue_reference<_BinaryPredicate>::type>
- (__first, __last, __count, __value_, __pred, typename iterator_traits<_ForwardIterator>::iterator_category());
+ (__first, __last, __convert_to_integral(__count), __value_, __pred,
+ typename iterator_traits<_ForwardIterator>::iterator_category());
}
template <class _ForwardIterator, class _Size, class _Tp>
@@ -1681,7 +1682,8 @@
search_n(_ForwardIterator __first, _ForwardIterator __last, _Size __count, const _Tp& __value_)
{
typedef typename iterator_traits<_ForwardIterator>::value_type __v;
- return _VSTD::search_n(__first, __last, __count, __value_, __equal_to<__v, _Tp>());
+ return _VSTD::search_n(__first, __last, __convert_to_integral(__count),
+ __value_, __equal_to<__v, _Tp>());
}
// copy
@@ -1839,8 +1841,10 @@
!__is_random_access_iterator<_InputIterator>::value,
_OutputIterator
>::type
-copy_n(_InputIterator __first, _Size __n, _OutputIterator __result)
+copy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result)
{
+ typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
+ _IntegralSize __n = __orig_n;
if (__n > 0)
{
*__result = *__first;
@@ -1862,8 +1866,10 @@
__is_random_access_iterator<_InputIterator>::value,
_OutputIterator
>::type
-copy_n(_InputIterator __first, _Size __n, _OutputIterator __result)
+copy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result)
{
+ typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
+ _IntegralSize __n = __orig_n;
return _VSTD::copy(__first, __first + __n, __result);
}
@@ -2055,7 +2061,7 @@
_OutputIterator
fill_n(_OutputIterator __first, _Size __n, const _Tp& __value_)
{
- return _VSTD::__fill_n(__first, __n, __value_);
+ return _VSTD::__fill_n(__first, __convert_to_integral(__n), __value_);
}
// fill
@@ -2101,8 +2107,10 @@
template <class _OutputIterator, class _Size, class _Generator>
inline _LIBCPP_INLINE_VISIBILITY
_OutputIterator
-generate_n(_OutputIterator __first, _Size __n, _Generator __gen)
+generate_n(_OutputIterator __first, _Size __orig_n, _Generator __gen)
{
+ typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
+ _IntegralSize __n = __orig_n;
for (; __n > 0; ++__first, (void) --__n)
*__first = __gen();
return __first;
diff --git a/include/type_traits b/include/type_traits
index 914e859..c44cae6 100644
--- a/include/type_traits
+++ b/include/type_traits
@@ -3646,6 +3646,48 @@
#endif // _LIBCPP_UNDERLYING_TYPE
+
+template <class _Tp, bool = std::is_enum<_Tp>::value>
+struct __sfinae_underlying_type
+{
+ typedef typename underlying_type<_Tp>::type type;
+ typedef decltype(((type)1) + 0) __promoted_type;
+};
+
+template <class _Tp>
+struct __sfinae_underlying_type<_Tp, false> {};
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_ALWAYS_INLINE
+int __convert_to_integral(int __val) { return __val; }
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_ALWAYS_INLINE
+unsigned __convert_to_integral(unsigned __val) { return __val; }
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_ALWAYS_INLINE
+long __convert_to_integral(long __val) { return __val; }
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_ALWAYS_INLINE
+unsigned long __convert_to_integral(unsigned long __val) { return __val; }
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_ALWAYS_INLINE
+long long __convert_to_integral(long long __val) { return __val; }
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_ALWAYS_INLINE
+unsigned long long __convert_to_integral(unsigned long long __val) {return __val; }
+
+#ifndef _LIBCPP_HAS_NO_INT128
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_ALWAYS_INLINE
+__int128_t __convert_to_integral(__int128_t __val) { return __val; }
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_ALWAYS_INLINE
+__uint128_t __convert_to_integral(__uint128_t __val) { return __val; }
+#endif
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_ALWAYS_INLINE
+typename __sfinae_underlying_type<_Tp>::__promoted_type
+__convert_to_integral(_Tp __val) { return __val; }
+
#ifndef _LIBCPP_HAS_NO_ADVANCED_SFINAE
template <class _Tp>