On Sunday, 14 October 2012 at 07:14:25 UTC, Maxim Fomin wrote:
If this request is approved and compiler has opUnary definition
outside type (which suits better then alias
this) such function would hijack alias this.
Free functions cannot and must not ever hijack, i.e. modify
existing functionality of a type. Free functions should only be
able to add new functionality to a type. This is what currently
happens with alias this vs free function which is accessed
through UFCS:
struct B
{
void fun()
{
writeln("B.fun()");
}
}
struct A
{
B b;
alias b this;
}
void fun(A a)
{
writeln(".fun(A)");
}
void main()
{
A a;
a.fun(); // prints B.fun() as it should
}
It shouldn't be any different if fun was some operator function,
like opUnary; the free function mustn't hijack type A's existing
functionality (which is currently being provided to A by that
alias this thingy).
