(In reply to comment #0)
> mixin template innerMixin() {
> 
>   void someFunc( string s )() if( s == "tata" ) {
> 
>   }
> 
> }
> 
> mixin template outerMixin() {
> 
>   //If you comment out this function, it compiles and work.
>   void someFunc( string s )() if( s == "toto" ) {
> 
>   }
> 
> 
>   mixin innerMixin;
> 
> }
> 
> void main( string[] args ) {
> 
>   mixin outerMixin;
> 
>   static assert( __traits( compiles, mixin( "someFunc!\"tata\"()" ) ) ); //Does
> not pass.
> }
> 
> Shouldn't it work? Version is 2.064

K, if you move the "outer" "someFunc" into its own mixin template, like such:

mixin template otherInnerMixin() {

  void someFunc( string s )() if( s == "toto" ) {
  
  }

}

and change "outerMixin" for this:

mixin template outerMixin() {
 
  mixin innerMixin;
  mixin otherInnerMixin;

}

Then it works.

(In reply to comment #1)
> (In reply to comment #0)
> > mixin template innerMixin() {
> > 
> >   void someFunc( string s )() if( s == "tata" ) {
> > 
> >   }
> > 
> > }
> > 
> > mixin template outerMixin() {
> > 
> >   //If you comment out this function, it compiles and work.
> >   void someFunc( string s )() if( s == "toto" ) {
> > 
> >   }
> > 
> > 
> >   mixin innerMixin;
> > 
> > }
> > 
> > void main( string[] args ) {
> > 
> >   mixin outerMixin;
> > 
> >   static assert( __traits( compiles, mixin( "someFunc!\"tata\"()" ) ) ); //Does
> > not pass.
> > }
> > 
> > Shouldn't it work? Version is 2.064
> 
> K, if you move the "outer" "someFunc" into its own mixin template, like such:
> 
> mixin template otherInnerMixin() {
> 
>   void someFunc( string s )() if( s == "toto" ) {
> 
>   }
> 
> }
> 
> and change "outerMixin" for this:
> 
> mixin template outerMixin() {
> 
>   mixin innerMixin;
>   mixin otherInnerMixin;
> 
> }
> 
> Then it works.

Scratch that, it's working for this short example but not in my real world problem.

This is the expected behavior. The innerMixin introduces a new scope so the function that is constrainted to "toto" actually has priority over the function constrained to "tata". To achieve what you want you have to introduce innerMixin.someFunc in the same overload set as outerMixin.somefunc:

mixin template outerMixin() {
  
  
  mixin innerMixin im;
  alias somefunc = im.someFunc();

  //If you comment out this function, it compiles and work.
  void someFunc( string s )() if( s == "toto" ) {
  
  }
}

Then the code will compile.