Issuing compile-time warnings with line numbers?

[Andrej Mitrovic]

Ah, you're right. It should have been a compile-time argument, conv.to
actually works in CTFE:

import std.conv;

struct Bar { }
struct Foo
{
   this(int line = __LINE__)(Bar bar)
   {
       pragma(msg, "Warning: Constructing Foo with Bar incurs
precision loss. Line: " ~ to!string(line));
   }
}

void main()
{
   auto foo = Foo(Bar());
}

Unfortunately this is nearly impossible to use this way without making
*every* ctor templated. This is due to that bug where templated
functions can't overload against non-templated functions.

I guess I'll have to do without line numbers for now. But thanks for the tip.