CODEWITHSUNDEEP
c++stringconstructorinitializationinitializer-list
base 10
base 10

Reputation: 49

String constructor with a int is not printed

    1. string s6 {0};
    2. string s5 {'a','b',7};
    cout << "S6 ::: " << s6 << endl; 
    cout << "S5 ::: " << s5 << endl;
  1. Expect undefined behaviour 'nullptr' but does print an empty string.
  2. Prints ab not expected behaviour.

Running on QT5.. compiler clang on MacOs

Upvotes: 0

Views: 66

Answers (1)

Vlad from Moscow
Vlad from Moscow

Reputation: 310940

In the both cases

1. string s6 {0};
2. string s5 {'a','b',7};

there is used the constructor that accepts an initializer list.

In the second case the integer literal 7 can be represented in the type char. So there is no narrowing conversion.

Consider the following program.

#include <iostream>
#include <string>

int main() 
{
    std::string s6 {0};
    std::string s5 {'a','b',7};

    std::cout << s6.size() << ": ";

    for ( char c : s6 ) std::cout << static_cast<int>( c ) << ' ';
    std::cout << '\n';

    std::cout << s5.size() << ": ";

    for ( char c : s5 ) std::cout << static_cast<int>( c ) << ' ';
    std::cout << '\n';

    return 0;
}

Its output is

1: 0 
3: 97 98 7

Upvotes: 3

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