If the compiler knows that a function can never throw out, it might be able to generate smaller exception-handling tables for callers of that function.

If a call to a function results in a C++ exception being propagated from the call into the caller, the behavior is undefined.

This modifier is ignored when not compiling with exceptions enabled.

struct S
{
    ~S();
};
__declspec(nothrow) extern void f(void);
void g(void)
{
    S s;
    f();
}