mirrors/phobos
1
0
Fork 0
mirror of https://github.com/dlang/phobos.git synced 2025-05-01 23:50:31 +03:00
Code Issues Projects Releases Packages Wiki Activity Actions

Simplify min and max

Browse source
This commit is contained in:
Andrei Alexandrescu 2020-09-13 10:47:18 -04:00
parent 33b1c17540
commit 423f633fd7
1 changed files with 36 additions and 76 deletions
Download patch file Download diff file Expand all files Collapse all files

112
std/algorithm/comparison.d
View file

@ -1138,29 +1138,6 @@ range of range (of range...) comparisons.
assert(!"bar".equal(E()));
}
// MaxType
private template MaxType(T...)
if (T.length >= 1)
{
static if (T.length == 1)
{
alias MaxType = T[0];
}
else static if (T.length == 2)
{
static if (!is(typeof(T[0].min)))
alias MaxType = CommonType!T;
else static if (T[1].max > T[0].max)
alias MaxType = T[1];
else
alias MaxType = T[0];
}
else
{
alias MaxType = MaxType!(MaxType!(T[0 .. ($+1)/2]), MaxType!(T[($+1)/2 .. $]));
}
}
// levenshteinDistance
/**
Encodes $(HTTP realityinteractive.com/rgrzywinski/archives/000249.html,
@ -1570,31 +1547,37 @@ Returns:
See_Also:
$(REF maxElement, std,algorithm,searching)
*/
MaxType!T max(T...)(T args)
if (T.length >= 2)
auto max(T...)(T args)
if (T.length >= 2 && !is(CommonType!T == void))
{
//Get "a"
static if (T.length <= 2)
// Get left-hand side of the comparison.
static if (T.length == 2)
alias a = args[0];
else
auto a = max(args[0 .. ($+1)/2]);
auto a = max(args[0 .. ($ + 1) / 2]);
alias T0 = typeof(a);
//Get "b"
// Get right-hand side.
static if (T.length <= 3)
alias b = args[$-1];
alias b = args[$ - 1];
else
auto b = max(args[($+1)/2 .. $]);
auto b = max(args[($ + 1) / 2 .. $]);
alias T1 = typeof(b);
static assert(is(typeof(a < b)),
"Invalid arguments: Cannot compare types " ~ T0.stringof ~
" and " ~ T1.stringof ~ ".");
" and " ~ T1.stringof ~ " for ordering.");
//Do the "max" proper with a and b
// Compute the returned type.
static if (!is(typeof(T0.min)))
alias Result = CommonType!(T0, T1);
else
alias Result = Select!(T1.max > T0.max, T1, T0);
// Perform the computation.
import std.functional : lessThan;
immutable chooseB = lessThan!(T0, T1)(a, b);
return cast(typeof(return)) (chooseB ? b : a);
return cast(Result) (chooseB ? b : a);
}
///
@ -1640,38 +1623,6 @@ if (T.length >= 2)
assert(max(Date.max, Date.min) == Date.max);
}
// MinType
private template MinType(T...)
if (T.length >= 1)
{
static if (T.length == 1)
{
alias MinType = T[0];
}
else static if (T.length == 2)
{
static if (!is(typeof(T[0].min)))
alias MinType = CommonType!T;
else
{
enum hasMostNegative = is(typeof(mostNegative!(T[0]))) &&
is(typeof(mostNegative!(T[1])));
static if (hasMostNegative && mostNegative!(T[1]) < mostNegative!(T[0]))
alias MinType = T[1];
else static if (hasMostNegative && mostNegative!(T[1]) > mostNegative!(T[0]))
alias MinType = T[0];
else static if (T[1].max < T[0].max)
alias MinType = T[1];
else
alias MinType = T[0];
}
}
else
{
alias MinType = MinType!(MinType!(T[0 .. ($+1)/2]), MinType!(T[($+1)/2 .. $]));
}
}
// min
/**
Iterates the passed arguments and returns the minimum value.
@ -1690,31 +1641,40 @@ Returns:
See_Also:
$(REF minElement, std,algorithm,searching)
*/
MinType!T min(T...)(T args)
if (T.length >= 2)
auto min(T...)(T args)
if (T.length >= 2 && !is(CommonType!T == void))
{
//Get "a"
// Get the left-hand side of the comparison.
static if (T.length <= 2)
alias a = args[0];
else
auto a = min(args[0 .. ($+1)/2]);
auto a = min(args[0 .. ($ + 1) / 2]);
alias T0 = typeof(a);
//Get "b"
// Get the right-hand side.
static if (T.length <= 3)
alias b = args[$-1];
alias b = args[$ - 1];
else
auto b = min(args[($+1)/2 .. $]);
auto b = min(args[($ + 1) / 2 .. $]);
alias T1 = typeof(b);
static assert(is(typeof(a < b)),
"Invalid arguments: Cannot compare types " ~ T0.stringof ~
" and " ~ T1.stringof ~ ".");
" and " ~ T1.stringof ~ " for ordering.");
//Do the "min" proper with a and b
// Compute the returned type.
static if (!is(typeof(T0.min)))
alias Result = CommonType!(T0, T1);
else
static if (is(typeof(mostNegative!T0)) && is(typeof(mostNegative!T1)))
alias Result = Select!(mostNegative!T1 < mostNegative!T0, T1, T0);
else
alias Result = Select!(T1.max < T0.max, T1, T0);
// Engage!
import std.functional : lessThan;
immutable chooseB = lessThan!(T1, T0)(b, a);
return cast(typeof(return)) (chooseB ? b : a);
return cast(Result) (chooseB ? b : a);
}
///