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comparison qt/qtd/Meta.d @ 319:894d40eb89b6 signals

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new signals and slots syntax. have to use prefixes now: signal_fooed and slot_onFooed
author eldar_ins@eldar-laptop
date Fri, 25 Dec 2009 21:48:32 +0500
parents
children 5c6455c4889b
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318:ce07227f00c1 319:894d40eb89b6
1 module qt.qtd.Meta;
2
3 import std.traits;
4 import std.typetuple;
5
6 // Various compile time utilities
7
8 public bool ctfeStartsWith(T)(T[] source, T[] pattern)
9 {
10 return source.length >= pattern.length && source[0 .. pattern.length] == pattern[];
11 }
12
13 // compile-time toString, maybe to!string is already working in CT
14 string __toString(long v)
15 {
16 if (v == 0)
17 return "0";
18
19 string ret;
20
21 bool neg;
22 if (v < 0)
23 {
24 neg = true;
25 v = -v;
26 }
27
28 while (v != 0)
29 {
30 ret = cast(char)(v % 10 + '0') ~ ret;
31 v = cast(long)(v / 10);
32 }
33
34 if (neg)
35 ret = "-" ~ ret;
36
37 return ret;
38 }
39
40 // returns the type of a template parameter if there is one
41 template templateParam(U : V!(U), alias V)
42 {
43 alias U templateParam;
44 }
45
46 // to workaround buggy foreach, returns a tuple of Ts of size I
47 template Repeat(T, int I)
48 {
49 static if (!I) alias TypeTuple!() Repeat;
50 else alias TypeTuple!(T, Repeat!(T, I - 1)) Repeat;
51 }
52
53 //returns number of required function arguments, optional arguments excluded
54 int requiredArgCount(alias fn)() {
55 alias ParameterTypeTuple!(typeof(&fn)) P;
56 P p;
57 static if (P.length == 0)
58 return 0;
59
60 foreach(i, _; P)
61 {
62 static if (!__traits(compiles, fn(p[0..$-i-1])))
63 {
64 return p.length - i;
65 }
66 }
67 return 0;
68 }