I can't figure out how to make use of the full capacity of
buffers that are allocated by readln. Take the example code from
the documentation:
// Read lines from $(D stdin) and count words
void main()
{
char[] buf;
size_t words = 0;
while (!stdin.eof)
{
char[] line = buf;
stdin.readln(line);
if (line.length > buf.length)
buf = line;
words += line.split.length;
}
writeln(words);
}
When buf is not large enough to hold the line, readln will
allocate a new buffer to accomodate and this example shows how
you can save that new buffer to reuse the next time. The problem
is that the capacity of the new buffer is nowhere to be found.
readln only returns the line that was read which is only a slice
of the buffer that was allocated. The next time that readln is
called, it will not read past the slice even if the capacity of
the buffer it allocated was larger. This will cause a new
allocation/copy every time you read a line that was larger than
all the previous lines, even if a previous allocation was already
large enough. This seems like a big oversight to me, I must be
missing something right?
