Utf8 to Utf32 cast cost

[Daniel Kozák via Digitalmars-d-learn]

On Mon, 08 Jun 2015 10:51:53 +0000
weaselcat via Digitalmars-d-learn <digitalmars-d-learn at puremagic.com>
wrote:

> On Monday, 8 June 2015 at 10:49:59 UTC, Ilya Yaroshenko wrote:
> > On Monday, 8 June 2015 at 10:42:00 UTC, Kadir Erdem Demir wrote:
> >> I want to use my char array with awesome, cool std.algorithm 
> >> functions. Since many of this algorithms requires like slicing 
> >> etc.. I prefer to create my string with Utf32 chars. But by 
> >> default all strings literals are Utf8 for performance.
> >>
> >> With my current knowledge I use to!dhar to convert Utf8[](or 
> >> char[]) to Utf32[](or dchar[])
> >>
> >> dchar[] range = to!dchar("erdem".dup)
> >>
> >> How costly is this?
> >> Is there a way which I can have Utf32 string directly without 
> >> a cast?
> >
> > 1. dstring range = to!dstring("erdem"); //without dup
> > 2. dchar[] range = to!(dchar[])("erdem"); //mutable
> > 3. dstring range = "erdem"d; //directly
> > 4. dchar[] range = "erdem"d.dup; //mutable
> 
> what's wrong with http://dlang.org/phobos/std_utf.html#.toUTF32

from: http://dlang.org/phobos/std_encoding.html#.transcode

Supersedes:
This function supersedes std.utf.toUTF8(), std.utf.toUTF16() and
std.utf.toUTF32() (but note that to!() supersedes it more conveniently).