Fix PR41017 - Build failure with _LIBCPP_DEBUG=0 and non-const-ref
comparator for std::sort()
Our debug comparator assumed that the comparator it wraps would always
accepts the values by const ref. This isn't required by the standard.
This patch makes our __debug_less comparator forward the constness.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@355752 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/algorithm b/include/algorithm
index 7da753a..cb619c2 100644
--- a/include/algorithm
+++ b/include/algorithm
@@ -784,7 +784,7 @@
__debug_less(_Compare& __c) : __comp_(__c) {}
template <class _Tp, class _Up>
- bool operator()(const _Tp& __x, const _Up& __y)
+ bool operator()(_Tp& __x, _Up& __y)
{
bool __r = __comp_(__x, __y);
if (__r)
@@ -795,18 +795,18 @@
template <class _LHS, class _RHS>
inline _LIBCPP_INLINE_VISIBILITY
decltype((void)_VSTD::declval<_Compare&>()(
- _VSTD::declval<_LHS const&>(), _VSTD::declval<_RHS const&>()))
- __do_compare_assert(int, _LHS const& __l, _RHS const& __r) {
+ _VSTD::declval<_LHS &>(), _VSTD::declval<_RHS &>()))
+ __do_compare_assert(int, _LHS & __l, _RHS & __r) {
_LIBCPP_ASSERT(!__comp_(__l, __r),
"Comparator does not induce a strict weak ordering");
}
template <class _LHS, class _RHS>
inline _LIBCPP_INLINE_VISIBILITY
- void __do_compare_assert(long, _LHS const&, _RHS const&) {}
+ void __do_compare_assert(long, _LHS &, _RHS &) {}
};
-#endif // _LIBCPP_DEBUG
+#endif // _LIBCPP_DEBUG
// all_of
diff --git a/test/libcxx/algorithms/debug_less.pass.cpp b/test/libcxx/algorithms/debug_less.pass.cpp
index 247e07f..4f92854 100644
--- a/test/libcxx/algorithms/debug_less.pass.cpp
+++ b/test/libcxx/algorithms/debug_less.pass.cpp
@@ -20,8 +20,11 @@
#define _LIBCPP_ASSERT(x, m) ((x) ? (void)0 : throw ::DebugException())
#include <algorithm>
+#include <iterator>
#include <cassert>
+#include "test_macros.h"
+
template <int ID>
struct MyType {
int value;
@@ -210,10 +213,32 @@
}
}
+struct NonConstArgCmp {
+ bool operator()(int& x, int &y) const {
+ return x < y;
+ }
+};
+
+void test_non_const_arg_cmp() {
+ {
+ NonConstArgCmp cmp;
+ __debug_less<NonConstArgCmp> dcmp(cmp);
+ int x = 0, y = 1;
+ assert(dcmp(x, y));
+ assert(!dcmp(y, x));
+ }
+ {
+ NonConstArgCmp cmp;
+ int arr[] = {5, 4, 3, 2, 1};
+ std::sort(std::begin(arr), std::end(arr), cmp);
+ assert(std::is_sorted(std::begin(arr), std::end(arr)));
+ }
+}
+
int main(int, char**) {
test_passing();
test_failing();
test_upper_and_lower_bound();
-
- return 0;
+ test_non_const_arg_cmp();
+ return 0;
}