On Wednesday, 6 July 2016 at 10:25:44 UTC, zodd wrote:
Thank you for a great example! D's power still surprises me a
lot.
just be careful to not carry wrapper around for too long, so it
won't outlive it's parent.
p.s. or this (abomination, i know!). ripped out of one of my
monkeycoding projects:
import std.stdio;
template GST(string fldname, size_t l=__LINE__) {
private import std.conv : to;
private enum bgsn = "z_buildGST_"~l.to!string;
private enum gn = "get_"~fldname;
private enum sn = "set_"~fldname;
private enum ft = "typeof(cast()"~gn~")";
enum GST =
"private alias "~bgsn~"_T = "~ft~";"~
"public @property auto "~fldname~"() (in auto ref "~bgsn~"_T
v) { "~sn~"(v); return "~bgsn~"; }\n"~
"public @property auto "~fldname~"() () const { return
"~gn~"; }\n"~
"public @property auto "~fldname~"() () { return "~bgsn~";
}\n"~
"private auto "~bgsn~"(T=typeof(this)) () {\n"~
" static struct "~bgsn~"_st {\n"~
" T* _p;\n"~
" alias _g this;\n"~
" auto _g () inout { return _p."~gn~"; }\n"~
" ref auto opAssign() (in auto ref "~bgsn~"_T v) {
_p."~sn~"(v); return this; }\n"~
" ref auto opOpAssign(string op) (in auto ref "~bgsn~"_T
v) { _p."~sn~"(mixin(`_p."~gn~"`~op~`v`)); return this; }\n"~
" string toString () const { import std.conv : to; return
_p."~gn~".to!string; }\n"~
" }\n"~
" return "~bgsn~"_st(&this);\n"~
"}\n"~
"";
}
struct Foo {
int mVal;
this (int n) { mVal = n; }
int get_val () const {
//import core.stdc.stdio : printf; printf("getter\n");
return mVal+1000;
}
void set_val (int v) {
//import core.stdc.stdio : printf; printf("setter\n");
mVal = v%1000;
}
mixin(GST!"val");
}
void main () {
writeln(Foo(42).val = 45);
Foo foo;
foo.val = 1020;
writeln("mv: ", foo.mVal, " : ", foo.val);
foo.val += 15;
writeln("mv: ", foo.mVal, " : ", foo.val);
foo.val--;
writeln("mv: ", foo.mVal, " : ", foo.val);
int n = (foo.val += 6);
writeln("n: ", n);
writeln("mv: ", foo.mVal, " : ", foo.val);
}
