char[] and wchar[] could still define a put method, which would make them output ranges. This is worth a bug report.
"Ali Çehreli" <acehr...@yahoo.com> wrote in message news:jgh4a1$1286$1...@digitalmars.com... > This I knew: Being UTF-8 and UTF-16 encodings, and because those encodings > are variable-width, char[] and wchar[] cannot be RandomAccessRange ranges > (dchar[] can be): > > import std.range; > > void main() > { > assert(!isRandomAccessRange!( char[])); > assert(!isRandomAccessRange!(wchar[])); > assert( isRandomAccessRange!(dchar[])); > } > > What I've recently discovered is that for being variable-width encodings, > char[] and wchar[] cannot be used as OutputRange ranges either. This is > because strings are ranges of Unicode characters in D, so their .front > must return a dchar, and that dchar must be an rvalue in the cases of > char[] and wchar[], which cannot be assigned to. > > Only dchar[] has assignable elements: > > import std.range; > > void main() > { > assert(!hasAssignableElements!( char[])); > assert(!hasAssignableElements!(wchar[])); > assert( hasAssignableElements!(dchar[])); > } > > For that reason, only dchar[] can be used as OutputRange: > > import std.range; > > void main() > { > assert(!isOutputRange!( char[], char)); > assert(!isOutputRange!( char[], wchar)); > assert(!isOutputRange!( char[], dchar)); > > assert(!isOutputRange!(wchar[], char)); > assert(!isOutputRange!(wchar[], wchar)); > assert(!isOutputRange!(wchar[], dchar)); > > assert( isOutputRange!(dchar[], char)); > assert( isOutputRange!(dchar[], wchar)); > assert( isOutputRange!(dchar[], dchar)); > } > > Ali