On Friday, 23 February 2018 at 20:15:12 UTC, H. S. Teoh wrote:
> Now that I got your attention:
>
> 	https://issues.dlang.org/show_bug.cgi?id=18511
>
> tl;dr: A trivial piece of code, written as ostensibly "idiomatic D" with std.algorithm and std.range templates, compiles *an order of magnitude* slower than the equivalent hand-written loop.  The way the compiler compiles templates needs some serious improvement.
>
> (And this is why our current fast-fast-fast slogan annoys me so much. One can argue that it's misleading advertising, given that what's considered "idiomatic D", using features like templates and generic code that's highly-touted as D's strong points, compiles a whole order of magnitude slower than C-style D.  Makes me cringe every time I hear "fast code, fast". Our old slogan is a much more accurate description of the current state of things.)
>
>
> T

This particular slowdown happens because there are somehow depdencies on std.format.format which is instantiated.
Which has a ton of dependencies itself.