nxt.deepdup source code

1 /** Deep duplication.
2 
3     Add to Phobos somewhere.
4 
5     TODO: Support inout relevant for const?
6     See: http://forum.dlang.org/thread/hojk95$4mk$1@digitalmars.com
7  */
8 module nxt.deepdup;
9 
10 import core.internal.traits : Unqual;
11 import std.typecons : tuple, Tuple;
12 import std.meta : staticMap;
13 import std.traits : isDynamicArray, isStaticArray, isArray, isPointer;
14 import std.range.primitives : ElementType;
15 
16 alias TypeofDeepdup(T) = typeof(deepdup(T.init));
17 
18 ref Unqual!T deepdup(T)(T t)
19 if (is(T == struct) &&
20     !is(T.Types))
21 {
22     staticMap!(TypeofDeepdup, typeof(t.tupleof)) tup;
23     foreach (const i, Type; tup)
24         tup[i] = t.tupleof[i].deepdup;
25     return Unqual!T(tup);
26 }
27 
28 Tuple!(staticMap!(TypeofDeepdup, T.Types)) deepdup(T)(T t)
29 if (is(T.Types))
30 {
31     staticMap!(TypeofDeepdup, T.Types) tup;
32     foreach (const i, Type; tup)
33         tup[i] = t.field[i].deepdup;
34     return tuple(tup);
35 }
36 
37 Unqual!T deepdup(T)(T t)
38 if (is(T == class))
39 {
40     staticMap!(TypeofDeepdup, typeof(t.tupleof)) tup;
41     foreach (const i, Type; tup)
42         tup[i] = t.tupleof[i].deepdup;
43     return new Unqual!T(tup);
44 }
45 
46 TypeofDeepdup!(ElementType!T)[] deepdup(T)(T t)
47 if (isDynamicArray!T)
48 {
49     auto result = new TypeofDeepdup!(ElementType!T)[](t.length);
50     foreach (const i, elem; t)
51         result[i] = elem.deepdup;
52     return result;
53 }
54 
55 TypeofDeepdup!(ElementType!T)[T.length] deepdup(T)(T t)
56 if (isStaticArray!T)
57 {
58     TypeofDeepdup!(ElementType!T)[T.length] result = t;
59     foreach (ref elem; result)
60         elem = elem.deepdup;
61     return result;
62 }
63 
64 TypeofDeepdup!T* deepdup(T)(T* t)
65 {
66     return &deepdup(*t);
67 }
68 
69 Unqual!T deepdup(T)(T t) if (!is(T == struct) &&
70                              !is(T == class) &&
71                              !isArray!T &&
72                              !is(T.Types) &&
73                              !isPointer!T)
74 {
75     return cast(Unqual!T)t;
76 }
77 
78 @safe pure nothrow:
79 
80 ///
81 unittest
82 {
83     auto x = [1, 2, 3];
84     assert(x == x.dup);
85     auto y = x;
86     assert(&x[0] == &y[0]);
87     assert(&x[0] != &x.dup[0]);
88 }
89 
90 ///
91 unittest
92 {
93     auto x = [[1], [2], [3]];
94     auto y = x.dup;
95     x[0][0] = 11;
96     assert(x[0][0] == 11);
97     assert(y[0][0] == 11);
98 }
99 
100 ///
101 unittest
102 {
103     auto x = [[1], [2], [3]];
104     auto y = x.deepdup;
105     x[0][0] = 11;
106     assert(x[0][0] == 11);
107     assert(y[0][0] == 1);
108 }
109 
110 ///
111 unittest
112 {
113     auto x = [[1], [2], [3]];
114     auto y = x.deepdup;
115     x[0][0] = 11;
116     assert(x[0][0] == 11);
117     assert(y[0][0] == 1);
118 }
119 
120 ///
121 unittest
122 {
123     auto x = [[[1]], [[2]], [[3]]];
124     auto y = x.deepdup;
125     x[0][0][0] = 11;
126     assert(x[0][0][0] == 11);
127     assert(y[0][0][0] == 1);
128 }
129 
130 /// dup of static array
131 unittest
132 {
133     int[3] x = [1, 2, 3];
134     auto y = x.dup;
135     x[0] = 11;
136     assert(x[0] == 11);
137     assert(y[0] == 1);
138 }
139 
140 /// dup of static array of dynamic arrays
141 unittest
142 {
143     int[][3] x = [[1], [2], [3]];
144     auto y = x.dup;
145     x[0][0] = 11;
146     assert(x[0][0] == 11);
147     assert(y[0][0] == 11);
148 }
149 
150 /// deepdup of static array of dynamic arrays
151 unittest
152 {
153     int[][3] x = [[1], [2], [3]];
154     auto y = x.deepdup;
155     x[0][0] = 11;
156     assert(x[0][0] == 11);
157     assert(y[0][0] == 1);
158 }