future.traits0 source code

1 /**
2 Compatibility shim to allow code written against the latest `std.traits`
3 module to compile with older versions of D.
4 
5 Copyright: Copyright Thomas Stuart Bockman 2015
6 License: $(LINK2 http://www.boost.org/LICENSE_1_0.txt, Boost License 1.0).
7 Authors: Thomas Stuart Bockman
8 **/
9 
10 /* HACK: Added '0' to the end of the name to preventdub build -b docs
11          from overwriting the output of checkedint.traits */
12 module future.traits0; 
13 
14 public import std.traits;
15 static if (__VERSION__ < 2068)
16     alias CopyTypeQualifiers(From, To) = To; // HACK!
17 else
18 {
19     version(GNU) { static assert(false); }
20 }
21 
22 enum isUnqual(T) = is(T == Unqual!T);
23 enum isFixedPoint(T) = isIntegral!T || isSomeChar!T || isBoolean!T;
24 
25 template IntFromChar(N)
26     if (isSomeChar!N)
27 {
28     static if (N.sizeof == char.sizeof)
29         alias IntFromChar = ubyte;
30     else
31     static if (N.sizeof == wchar.sizeof)
32         alias IntFromChar = ushort;
33     else
34     static if (N.sizeof == dchar.sizeof)
35         alias IntFromChar = uint;
36     else
37         static assert(false);
38 }
39 template IntFromChar(N)
40     if (isIntegral!N)
41 {
42     alias IntFromChar = Unqual!N;
43 }
44 template Promoted(N)
45     if (isScalarType!N)
46 {
47     alias Promoted = CopyTypeQualifiers!(N, typeof(N.init + N.init));
48 }
49 
50 alias CallType(alias callable, ArgTypes...) = typeof(function()
51     {
52         import std.typecons : Tuple;
53         return callable(Tuple!(ArgTypes)().expand);
54     }());
55 alias OpType(string op, T) = typeof(function()
56     {
57         T t;
58         return mixin(op ~ "t");
59     }());
60 alias OpType(T, string op, V) = typeof(function()
61     {
62         T t;
63         V v = 1; // Prevent "divide by zero" errors at CTFE
64         return mixin("t " ~ op ~ " v");
65     }());
66 
67 template precision(N)
68     if (isScalarType!N)
69 {
70     import future.bitop : bsr;
71     static if (isFloatingPoint!N)
72         enum int precision = N.mant_dig;
73     else static if (isSomeChar!N)
74         enum int precision = N.sizeof * 8; // dchar may hold values greater than dchar.max
75     else
76         enum int precision = bsr(N.max) + 1;
77 }