Checking @nogc-ness of an Allocator.allocate()

[Simen Kjærås]

On Thursday, 11 January 2018 at 12:32:54 UTC, Per Nordlöw wrote:
> Is this an ok implementation:
>
> enum bool isNogc(alias fun) = (isCallable!fun &&
>                                (functionAttributes!fun &
>                                 FunctionAttribute.nogc));
>
> @safe pure nothrow @nogc unittest
> {
>     static int foo(int x) @nogc pure nothrow;
>     static int goo(int x) pure nothrow;
>     static assert(isNogc!foo);
>     static assert(!isNogc!goo);
> }

Seems to be working fine. I'd go with this version for perhaps a 
bit more brevity and clarity:

enum bool isNogc(alias fun) = hasFunctionAttributes!(fun, 
"@nogc");

Both functionAttributes and hasFunctionAttributes already check 
that the argument is a callable (which function attributes should 
"foo" have?), so that's unnecessary.

--
   Simen