www.digitalmars.com         C & C++   DMDScript  

digitalmars.D.learn - std.utf.decode("dlang", 1)

reply "Algo" <algo nonsense.com> writes:
void main()
{
       import std.utf;
       decode("dlang", 1);
}

Error: template std.utf.decode cannot deduce function from
argument types !()(string, int), candidates are:
D:\msc\D\dmd2\windows\bin\..\..\src\phobos\std\utf.d(924):
std.utf.decode(S)(auto ref S str, ref size_t index) if
(!isSomeString!S && isRandomAccessRange!S && hasSlicing!S &&
hasLength!S && isSomeChar!(ElementType!S))
D:\msc\D\dmd2\windows\bin\..\..\src\phobos\std\utf.d(942):
std.utf.decode(S)(auto ref S str, ref size_t index) if
(isSomeString!S)

why doesn't "decode(S)(auto ref S str, ref size_t index) if
(isSomeString!S)" correspond?
Sep 17 2014
next sibling parent reply "Algo" <algo nonsense.com> writes:
On Thursday, 18 September 2014 at 06:09:54 UTC, Algo wrote:
 void main()
 {
       import std.utf;
       decode("dlang", 1);
 }

 Error: template std.utf.decode cannot deduce function from
 argument types !()(string, int), candidates are:
 D:\msc\D\dmd2\windows\bin\..\..\src\phobos\std\utf.d(924):
 std.utf.decode(S)(auto ref S str, ref size_t index) if
 (!isSomeString!S && isRandomAccessRange!S && hasSlicing!S &&
 hasLength!S && isSomeChar!(ElementType!S))
 D:\msc\D\dmd2\windows\bin\..\..\src\phobos\std\utf.d(942):
 std.utf.decode(S)(auto ref S str, ref size_t index) if
 (isSomeString!S)

 why doesn't "decode(S)(auto ref S str, ref size_t index) if
 (isSomeString!S)" correspond?
rvalues cannot be ref it seems
Sep 17 2014
parent =?UTF-8?B?QWxpIMOHZWhyZWxp?= <acehreli yahoo.com> writes:
On 09/17/2014 11:23 PM, Algo wrote:
 On Thursday, 18 September 2014 at 06:09:54 UTC, Algo wrote:
 void main()
 {
       import std.utf;
       decode("dlang", 1);
 }

 Error: template std.utf.decode cannot deduce function from
 argument types !()(string, int), candidates are:
 D:\msc\D\dmd2\windows\bin\..\..\src\phobos\std\utf.d(924):
 std.utf.decode(S)(auto ref S str, ref size_t index) if
 (!isSomeString!S && isRandomAccessRange!S && hasSlicing!S &&
 hasLength!S && isSomeChar!(ElementType!S))
 D:\msc\D\dmd2\windows\bin\..\..\src\phobos\std\utf.d(942):
 std.utf.decode(S)(auto ref S str, ref size_t index) if
 (isSomeString!S)

 why doesn't "decode(S)(auto ref S str, ref size_t index) if
 (isSomeString!S)" correspond?
rvalues cannot be ref it seems
Yes. Interestingly, in D rvalues cannot be bound even to const ref. void main() { import std.stdio; import std.utf; size_t index = 1; dchar decoded = decode("dlang", index); writefln("decoded '%s', next character is at index %s.", decoded, index); } The output: decoded 'l', next character is at index 2. Ali
Sep 17 2014
prev sibling parent "AsmMan" <jckj33 gmail.com> writes:
On Thursday, 18 September 2014 at 06:09:54 UTC, Algo wrote:
 void main()
 {
       import std.utf;
       decode("dlang", 1);
 }

 Error: template std.utf.decode cannot deduce function from
 argument types !()(string, int), candidates are:
 D:\msc\D\dmd2\windows\bin\..\..\src\phobos\std\utf.d(924):
 std.utf.decode(S)(auto ref S str, ref size_t index) if
 (!isSomeString!S && isRandomAccessRange!S && hasSlicing!S &&
 hasLength!S && isSomeChar!(ElementType!S))
 D:\msc\D\dmd2\windows\bin\..\..\src\phobos\std\utf.d(942):
 std.utf.decode(S)(auto ref S str, ref size_t index) if
 (isSomeString!S)

 why doesn't "decode(S)(auto ref S str, ref size_t index) if
 (isSomeString!S)" correspond?
I was having same issue a while ago. But I realized I was using function in the wrong way with string type and passing a size_t in the 2th argument. You can see use of decode(val, size) in the standard library but call it in your code result in an error. it worked: string s = readText("file"); decode(cast(ubyte[]) s); I'm not sure why you're trying to pass a string literal as argument because it does need a memory location to change to new memory location, where bytes skiped end. That's why it does use ref.
Sep 18 2014