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Fix issue 19525

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Biotronic 2020-05-29 00:10:34 +02:00
parent 5ebf458b50
commit fd59b6a92e
1 changed files with 19 additions and 5 deletions
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24
std/algorithm/iteration.d
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@ -6427,7 +6427,9 @@ $(DDSUBLINK spec/type,integer-promotions, integral promotion)).
A seed may be passed to `sum`. Not only will this seed be used as an initial
value, but its type will override all the above, and determine the algorithm
and precision used for summation.
and precision used for summation. If a seed is not passed, one is created with
the value of `typeof(r.front + r.front)(0)`, or `typeof(r.front + r.front).zero`
if no constructor exists that takes an int.
Note that these specialized summing algorithms execute more primitive operations
than vanilla summation. Therefore, if in certain cases maximum speed is required
@ -6449,10 +6451,15 @@ if (isInputRange!R && !isInfinite!R && is(typeof(r.front + r.front)))
alias Seed = typeof(E.init + 0.0); //biggest of double/real
else
alias Seed = typeof(r.front + r.front);
static assert(is(typeof(Unqual!Seed(0))),
"Could not initiate an initial value for " ~ (Unqual!Seed).stringof
~ ". Please supply an initial value manually.");
return sum(r, Unqual!Seed(0));
static if (is(typeof(Unqual!Seed(0))))
enum seedValue = Unqual!Seed(0);
else static if (is(typeof({ Unqual!Seed tmp = Seed.zero; })))
enum Unqual!Seed seedValue = Seed.zero;
else
static assert(false,
"Could not initiate an initial value for " ~ (Unqual!Seed).stringof
~ ". Please supply an initial value manually.");
return sum(r, seedValue);
}
/// ditto
auto sum(R, E)(R r, E seed)
@ -6693,6 +6700,13 @@ private auto sumKahan(Result, R)(Result result, R r)
assert(repeat(1.0, n).sum == n);
}
// Issue 19525
@safe unittest
{
import std.datetime : Duration, minutes;
assert([1.minutes].sum() == 1.minutes);
}
/**
Finds the mean (colloquially known as the average) of a range.