Why __traits(compile,...) fails here?

[Zhenya]

import std.stdio;

template isType(alias s)
{
        enum isType = !__traits(compiles,mixin("typeof(s)"));
}
void main()
{
//	writeln(isType!int);// Error: template instance isType!(int) 
isType!(int) does not match template declaration isType(alias s)
        writeln(__traits(compiles,mixin("typeof(int)")));//write: false
}