gistfile1.d

import std.stdio;

class Foo
{
    void foo() { writeln("foo1"); }
    void foo() { writeln("foo2"); }
    void bar() { writeln("bar"); }
};

int main()
{
    auto f = new Foo();
    f.bar();
    return 0;
}

gistfile2.txt

dmd test.d
test.o: In function `_D4test3Foo3fooMFZv':
test.d:(.text._D4test3Foo3fooMFZv+0x60): multiple definition of `_D4test3Foo3fooMFZv'
test.o:test.d:(.text._D4test3Foo3fooMFZv+0x0): first defined here
collect2: error: ld returned 1 exit status