mixin template had error by calling shared function

[Vlasov Roman via Digitalmars-d-learn]

I have this code

import std.stdio;
mixin template Template(void function() func1, void function() 
func2) {

        void    to() {
                func1();
                func2();
        }
};

class SomeClass {
        mixin Template!(&func, &func23);

        void func() {
                writeln("First function!");
        }

        void func23() {
                writeln("First function!");
        }

        void toTemplate() {
                to();
        }
}

void main() {
        SomeClass a = new SomeClass();

        a.toTemplate();
}

After running the program give me SIGSEGV in func23();

Terminal with gdb:

Program received signal SIGSEGV, Segmentation fault.
0x0000000000428352 in invariant._d_invariant(Object) ()
(gdb) up
#1  0x00000000004257f7 in main.SomeClass.func23() ()


Manjaro Linux 0.9.0 x86_64
dmd 2.066
Kernel 3.14.4