Bug 1525 – Can't instantiate template with bogus error messages

template k(U:V[C]) { void func(U a, C v){writefln("hello");}; } int[char]v; char m; k!(int[char]).func(v); gives me: abc.d(7): variable abc.v conflicts with variable abc.v at abc.d(5) abc.d(1): Error: identifier 'C' is not defined abc.d(1): Error: index is not a type or an expression abc.d(1): Error: identifier 'V' is not defined abc.d(1): Error: V is used as a type modify the last line to k!(int[char]).func(v,m) gives me: abc.d(7): found ',' when expecting ')' abc.d(7): semicolon expected, not 'm' abc.d(7): no identifier for declarator m abc.d(7): semicolon expected, not ')' abc.d(7): Declaration expected, not ')'

this bug is for nicer error messages maybe hint user that missing template list of (U:V[C],C) for such a specialization.

INVALID I think but.... template k(U:V[C], V, C) { void func(U a, C v){writefln("hello");}; } works, and can be instantiated as k!(int[int]).

Dmd now complains that V and C are undefined (dmd 1.068 & 2.053) which correctly identifies the problem. testx.d(1): Error: undefined identifier C, did you mean template k(U : V[C])? testx.d(1): Error: undefined identifier V, did you mean template k(U : V[_error_ ])?