[Bug c++/46224] New: Enhancement: Issue warning when matching placement delete operator is missing

[trial_ali at gmx dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46224

           Summary: Enhancement: Issue warning when matching placement
                    delete operator is missing
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: trial_...@gmx.net


Consider the appended sample program - it has a matching placement delete
operator which gets called since the corresponding new throws. When changing
the signature (either unintentional or simply by not providing such a matching
placement delete operator at all) of the placement delete operator a warning
should be issued such that the programmer sees that there is the danger of
memory not being freed.

VC++ issues a warning C4291 in those cases: "no matching operator delete found;
memory will not be freed if initialization throws an exception"



#include <iostream>
#include <new>
#include <cstdlib>

using namespace std;

#define MY_NEW new(__FILE__,__LINE__)

void* operator new(
    std::size_t num_bytes,
    const char*,
    int) throw (std::bad_alloc)
{
    return malloc(num_bytes);
}

void operator delete(
    void*,
    const char*,
    int)
{
    cout << "YES" << endl;
}

struct Foo
{
    Foo() { throw int(); }
};

int main()
{
    Foo* f;
    try {
    f = MY_NEW Foo();
    }
    catch (int&) {}
    return 0;
}