Re: A specifier readf() for BigInt

[Ivan Kazmenko via Digitalmars-d-learn]

On Monday, 16 February 2015 at 19:52:20 UTC, Dennis Ritchie wrote:
Hi.
And how to read Data from the input stream?
import std.stdio;
import std.bigint;

void main() {

        BigInt n;

        readf(" %?", &n);

        writeln(n);
}

The readf function does not seem to support reading BigInts 
directly.

However, you can read a string and construct a BigInt from it, 
either by std.conv.to or directly invoking the constructor:

import std.algorithm, std.bigint, std.conv, std.stdio, std.string;

void main () {
    // read a line of space-separated BigInts and print their sum:
    readln.split.map !(to!BigInt).sum.writeln;
    // read a line containing one BigInt and print it squared:
    auto s = BigInt (readln.strip);
    writeln (s ^^ 2);
}