@property wrapper in D

import std.stdio;

struct Wrapper(O, string getter, string setter) {
    auto get() {
        mixin("return obj."~getter~";");
    }

    Wrapper opAssign(T)(T value) {
        mixin("obj."~setter~"(value);");
        return this;
    }

    Wrapper opOpAssign(string op, T)(T value) {
        mixin("obj."~setter~"(obj."~getter~op~"value);");
        return this;
    }

    private O* obj;

    alias get this;
}
mixin template InjectWrapper(string name, string getter, string setter)
{
    mixin(
    "@property auto "~name~"(this T)() {"~
    "   return Wrapper!(T, getter, setter)(&this);"~
    "}");
    mixin(
    "@property auto "~name~"(this T, U)(U value) {"~
    "   return Wrapper!(T, getter, setter)(&this) = value;"~
    "}");
}

struct Foo {
    mixin InjectWrapper!("value","getValue", "setValue");
private:
    int value_;

    int getValue() const {
        return value_;
    }

    void setValue(int value) {
        value_ = value;
    }
}

int main(string[] args) {
    Foo foo;
    foo.value = 20;
    writeln(foo.value_);

    foo.value += 15;
    writeln(foo.value_);


    foo.value--;
    writeln(foo.value_);
    return 0;
}