grain.utility source code

1 /**
2    A module of utility functions
3  */
4 module grain.utility;
5 
6 import std.typecons  : isTuple, tuple;
7 
8 /// non-tuple to tuple. tuple to tuple
9 auto toTuple(T)(T t) {
10     static if (isTuple!T) {
11         return t;
12     } else {
13         return tuple(t);
14     }
15 }
16 
17 /// single element tuple to element. the other tuple to tuple
18 auto fromTuple(T)(T t) {
19     static if (t.length == 0) {
20         return t[0];
21     } else {
22         return t;
23     }
24 }
25 
26 /// unsafe cast of array (e.g., int[] -> size_t[])
27 Dst[N] castArray(Dst, Src, size_t N)(Src[N] src) {
28     Dst[N] dst;
29     static foreach (i; 0 .. N) {
30         dst[i] = cast(Dst) src[i];
31     }
32     return dst;
33 }
34 
35 version (LDC) {
36     public import ldc.attributes : optStrategy;
37 } else {
38     /// usage @optStrategy("none")
39     struct optStrategy {
40         string s;
41     }
42 }