opAssign overload question

[Ali Çehreli]

On 04/25/2013 11:37 AM, gedaiu wrote:> Hi folks,
 >
 > i have this struct:

Reduced code:

import std.stdio;

void foo(bool b)
{
     writeln("bool");
}

void foo(long l)
{
     writeln("long");
}

void main()
{
     foo(1);
}

The bool overload gets called...

 > Can anyone tell me why the compiler call opAssign(bool val) and not
 > opAssign(long val). I am passing an long value not a bool one.

The type of literal 1 is int, not long. So, both functions are matched 
with implicit conversions. According to "Function Overloading" here:

   http://dlang.org/function.html

The match is later resolved by "If two or more functions have the same 
match level, then partial ordering is used to try to find the best 
match. Partial ordering finds the most specialized function."

If bool is considered to be more specialized than long, then the 
compiler is behaving according to spec. It is very confusing indeed. 
Especially, considering that an int *variable* would be matched to long:

     auto i = 1;
     foo(i);

Now the long overload gets called!

Ali