out_value is broken

[fhoefling]

The policy "out_value" seems to be broken (for a long time?), it is also not covered by the tests (test_policies.cpp has "pure_out_value" only). The following example is copied from the luabind documentation, GCC and Clang generate an error about calling a non-static member function:

.../luabind/out_value_policy.hpp:126:71: error: cannot call member function ‘int luabind::native_converter_base::match(lua_State*, luabind::detail::by_value, int) [with T = float; Derived = luabind::default_converter; lua_State = lua_State]’ without object
             return converter::match(L, LUABIND_DECORATE_TYPE(T), index);

Example:

#include "test.hpp"

#include 
#include 

void f(float& val) { val = val + 10.f; }

void test_main(lua_State* L)
{
    using namespace luabind;

    module(L)
    [
         def("f", &f, out_value(_1)) // compiles with "pure_out_value"
    ];

    // out_value
    DOSTRING(L,
        "a = f(5)\n"
        "assert(a == 15)");
}