@safe pure unittest
{
    import std.demangle;

    // int b in module a
    assert(demangle("_D1a1bi") == "int a.b");
    // char array foo in module test
    assert(demangle("_D4test3fooAa") == "char[] test.foo");
}

@system unittest
{
    import std.demangle;

    import std.ascii : isAlphaNum;
    import std.algorithm.iteration : chunkBy, joiner, map;
    import std.algorithm.mutation : copy;
    import std.conv : to;
    import std.demangle : demangle;
    import std.functional : pipe;
    import std.stdio : stdin, stdout;

    void main()
    {
        stdin.byLineCopy
            .map!(
                l => l.chunkBy!(a => isAlphaNum(a) || a == '_')
                      .map!(a => a[1].pipe!(to!string, demangle)).joiner
            )
            .copy(stdout.lockingTextWriter);
    }
}