[gcc r13-9485] libstdc++: Avoid bogus -Walloc-size-larger-than warning in test [PR116212]

[Jonathan Wakely]

https://gcc.gnu.org/g:30a0a942007ac01601c6493b558b747d6a5b6371

commit r13-9485-g30a0a942007ac01601c6493b558b747d6a5b6371
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Tue Apr 1 11:02:43 2025 +0100

    libstdc++: Avoid bogus -Walloc-size-larger-than warning in test [PR116212]
    
    The compiler can't tell that the vector size fits in int, so it thinks
    it might overflow to a negative value, which would then be a huge
    positive size_t.  In reality, the vector size never exceeds five.
    
    There's no warning on trunk, so just change the local variable to use
    type unsigned so that we get rid of the warning on the branches.
    
    libstdc++-v3/ChangeLog:
    
            PR libstdc++/116212
            * testsuite/20_util/specialized_algorithms/uninitialized_move/constrained.cc:
            Use unsigned for vector size.

Diff:
---
 .../20_util/specialized_algorithms/uninitialized_move/constrained.cc    | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_move/constrained.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_move/constrained.cc
index 23dcefdd3dfa..a4343ae8f5bb 100644
--- a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_move/constrained.cc
+++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_move/constrained.cc
@@ -51,7 +51,7 @@ test01(std::vector<T> ix)
     {
       ix = saved_ix;
 
-      int size = ix.size();
+      unsigned size = ix.size();
       auto buffer = std::unique_ptr<char[]>(new char[sizeof(T)*size]);
       std::span<T> rx((T *)buffer.get(), size);