The following code:
import std.conv;
void main(string[] args)
{
auto t = to!double();
}
Gives the error message when compiled with dmd 2.066:
/usr/include/dlang/dmd/std/conv.d(278): Error: template instance isRawStaticArray!() does not match template declaration isRawStaticArray(T, A...)
When compiling with dmd 2.065:
/opt/compilers/dmd2/include/std/conv.d(280): Error: template instance isRawStaticArray!() does not match template declaration isRawStaticArray(T, A...) test.d(5): Error: template std.conv.to cannot deduce function from argument types !(double)(), candidates are: /opt/compilers/dmd2/include/std/conv.d(277): std.conv.to(T)
The error message from dmd 2.065 is cleary better and actually points to the correct file/line where the issue is located. The error dmd 2.066 gives is completely useless in actually finding the issue.