class C {} struct S1 { void opAssign(int*) {} } static assert(!isNullTestable!S1); static assert( isNullTestable!C); static assert( isNullTestable!(int*)); struct S2 {} static assert(!isNullTestable!S2); static assert(!isNullTestable!int); class C2 { @disable this(); } static assert(isNullTestable!C2);
Returns true of T can be check with null using an if statement