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Move 'forward' to std.functional.

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This commit is contained in:
H. S. Teoh 2015-02-16 10:54:58 -08:00
parent e8ce21d16a
commit a43e8d22cd
2 changed files with 99 additions and 109 deletions
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109
std/algorithm/package.d
View file

@ -183,115 +183,6 @@ public import std.algorithm.setops;
public import std.algorithm.searching; public import std.algorithm.searching;
public import std.algorithm.sorting; public import std.algorithm.sorting;
// FIXME
import std.functional; // : unaryFun, binaryFun;
import std.range.primitives;
// FIXME
import std.range; // : SortedRange;
import std.traits;
// FIXME
import std.typecons; // : tuple, Tuple;
// FIXME
import std.typetuple; // : TypeTuple, staticMap, allSatisfy, anySatisfy;
version(unittest) debug(std_algorithm) import std.stdio;
/**
Forwards function arguments with saving ref-ness.
*/
template forward(args...)
{
import std.typetuple;
static if (args.length)
{
alias arg = args[0];
static if (__traits(isRef, arg))
alias fwd = arg;
else
@property fwd()(){ return move(arg); }
alias forward = TypeTuple!(fwd, forward!(args[1..$]));
}
else
alias forward = TypeTuple!();
}
///
@safe unittest
{
class C
{
static int foo(int n) { return 1; }
static int foo(ref int n) { return 2; }
}
int bar()(auto ref int x) { return C.foo(forward!x); }
assert(bar(1) == 1);
int i;
assert(bar(i) == 2);
}
///
@safe unittest
{
void foo(int n, ref string s) { s = null; foreach (i; 0..n) s ~= "Hello"; }
// forwards all arguments which are bound to parameter tuple
void bar(Args...)(auto ref Args args) { return foo(forward!args); }
// forwards all arguments with swapping order
void baz(Args...)(auto ref Args args) { return foo(forward!args[$/2..$], forward!args[0..$/2]); }
string s;
bar(1, s);
assert(s == "Hello");
baz(s, 2);
assert(s == "HelloHello");
}
@safe unittest
{
auto foo(TL...)(auto ref TL args)
{
string result = "";
foreach (i, _; args)
{
//pragma(msg, "[",i,"] ", __traits(isRef, args[i]) ? "L" : "R");
result ~= __traits(isRef, args[i]) ? "L" : "R";
}
return result;
}
string bar(TL...)(auto ref TL args)
{
return foo(forward!args);
}
string baz(TL...)(auto ref TL args)
{
int x;
return foo(forward!args[3], forward!args[2], 1, forward!args[1], forward!args[0], x);
}
struct S {}
S makeS(){ return S(); }
int n;
string s;
assert(bar(S(), makeS(), n, s) == "RRLL");
assert(baz(S(), makeS(), n, s) == "LLRRRL");
}
@safe unittest
{
ref int foo(return ref int a) { return a; }
ref int bar(Args)(auto ref Args args)
{
return foo(forward!args);
}
static assert(!__traits(compiles, { auto x1 = bar(3); })); // case of NG
int value = 3;
auto x2 = bar(value); // case of OK
}
/** /**
Specifies whether the output of certain algorithm is desired in sorted Specifies whether the output of certain algorithm is desired in sorted
format. format.

99
std/functional.d
View file

@ -1359,3 +1359,102 @@ unittest {
static assert(! is(typeof(dg_xtrnC) == typeof(dg_xtrnD))); static assert(! is(typeof(dg_xtrnC) == typeof(dg_xtrnD)));
} }
} }
/**
Forwards function arguments with saving ref-ness.
*/
template forward(args...)
{
import std.typetuple;
static if (args.length)
{
import std.algorithm.mutation : move;
alias arg = args[0];
static if (__traits(isRef, arg))
alias fwd = arg;
else
@property fwd()(){ return move(arg); }
alias forward = TypeTuple!(fwd, forward!(args[1..$]));
}
else
alias forward = TypeTuple!();
}
///
@safe unittest
{
class C
{
static int foo(int n) { return 1; }
static int foo(ref int n) { return 2; }
}
int bar()(auto ref int x) { return C.foo(forward!x); }
assert(bar(1) == 1);
int i;
assert(bar(i) == 2);
}
///
@safe unittest
{
void foo(int n, ref string s) { s = null; foreach (i; 0..n) s ~= "Hello"; }
// forwards all arguments which are bound to parameter tuple
void bar(Args...)(auto ref Args args) { return foo(forward!args); }
// forwards all arguments with swapping order
void baz(Args...)(auto ref Args args) { return foo(forward!args[$/2..$], forward!args[0..$/2]); }
string s;
bar(1, s);
assert(s == "Hello");
baz(s, 2);
assert(s == "HelloHello");
}
@safe unittest
{
auto foo(TL...)(auto ref TL args)
{
string result = "";
foreach (i, _; args)
{
//pragma(msg, "[",i,"] ", __traits(isRef, args[i]) ? "L" : "R");
result ~= __traits(isRef, args[i]) ? "L" : "R";
}
return result;
}
string bar(TL...)(auto ref TL args)
{
return foo(forward!args);
}
string baz(TL...)(auto ref TL args)
{
int x;
return foo(forward!args[3], forward!args[2], 1, forward!args[1], forward!args[0], x);
}
struct S {}
S makeS(){ return S(); }
int n;
string s;
assert(bar(S(), makeS(), n, s) == "RRLL");
assert(baz(S(), makeS(), n, s) == "LLRRRL");
}
@safe unittest
{
ref int foo(return ref int a) { return a; }
ref int bar(Args)(auto ref Args args)
{
return foo(forward!args);
}
static assert(!__traits(compiles, { auto x1 = bar(3); })); // case of NG
int value = 3;
auto x2 = bar(value); // case of OK
}