readf bug in the std.stdio

[Can Alpay Çiftçi]

Code:
import std.stdio;
 
void main() {
 
    char a;
    wchar b;
    dchar c;
    
    readf("%s %s %s", &a,&b,&c);
 
}


Error :

dmd -w -c "isimsiz.d" (C:\Program Files\Geany )
C:\D\dmd2\windows\bin\..\..\src\phobos\std\format.d(441): Error: template std.format.unformatValue(T,Range,Char) if (isArray!(T) && !isSomeString!(T)) does not match any function template declaration
C:\D\dmd2\windows\bin\..\..\src\phobos\std\format.d(441): Error: template std.format.unformatValue(T,Range,Char) if (isArray!(T) && !isSomeString!(T)) cannot deduce template function from argument types !(char)(LockingTextReader,FormatSpec!(char))
C:\D\dmd2\windows\bin\..\..\src\phobos\std\format.d(441): Error: template instance errors instantiating template

Is that intended, or a bug?

Please note that this works:

    int i;
    readf("%s", &i);