• Andrey (5/9) May 13 2020 Fold and reduce doesn't work:
• H. S. Teoh (5/8) May 13 2020 data.map!(s => s.length).sum;
• MoonlightSentinel (8/17) May 13 2020 The problem is that you provide a uint as seed (which determines
• Andrey (1/1) May 14 2020 Thanks everyone.

Andrey <saasecondbox yandex.ru> writes:

Hi,
I want to sum lengths of all strings in array:
 auto data = ["qwerty", "az", "!!!!"];

Fold and reduce doesn't work:
 auto result = data.fold!`a + b.length`(0U);

gives error:
 static assert:  "Incompatible function/seed/element: 
 binaryFun/uint/string"

How to do it in one line?

"H. S. Teoh" <hsteoh quickfur.ath.cx> writes:

On Wed, May 13, 2020 at 01:52:13PM +0000, Andrey via Digitalmars-d-learn wrote:
 Hi,
 I want to sum lengths of all strings in array:
 auto data = ["qwerty", "az", "!!!!"];


data.map!(s => s.length).sum;


T

-- 
It only takes one twig to burn down a forest.

MoonlightSentinel <moonlightsentinel disroot.org> writes:

On Wednesday, 13 May 2020 at 13:52:13 UTC, Andrey wrote:
 Hi,
 I want to sum lengths of all strings in array:
 auto data = ["qwerty", "az", "!!!!"];

 Fold and reduce doesn't work:
 auto result = data.fold!`a + b.length`(0U);

 gives error:
 static assert:  "Incompatible function/seed/element: 
 binaryFun/uint/string"

 How to do it in one line?

The problem is that you provide a uint as seed (which determines 
the type of the accumulated value) but your function returns a 
ulong (or rather size_t).

You can fix this by changing the type of your seed, either use 
ulong or size_t.

auto result = data.fold!`a + b.length`(0UL);

auto result = data.fold!`a + b.length`(size_t(0));

Andrey <saasecondbox yandex.ru> writes:

Thanks everyone.