4.2.5. __declspec(nothrow)
The __declspec(nothrow) attribute asserts that a call to a function never results in a C++ exception being propagated from the call into the caller.
The ARM library headers automatically add this qualifier to declarations of C functions that, according to the ISO C Standard, can never throw.
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();
}