invalid conversion from ‘const char*’ to ‘char’

[Shlomo]

I'm trying to compile the following example from Koenig/Moo's Accelerated C++:

  1 #include <iostream>
  2 #include <string>
  3 
  4 int main()
  5 {
  6     std::cout << "enter name: ";
  7     std::string name;
  8     std::cin >> name;
  9 
 10     const std::string greeting = "Hello "+name+"!";
 11     const std::string spaces(greeting.size(), " ");
 12     const std::string second = "* "+spaces+" *";
 13     const std::string first(second.size(), "*");
 14 
 15     std::cout << std::endl;
 16     std::cout << first << std::endl;
 17     std::cout << second << std::endl;
 18     std::cout << "* " << greeting << " *" << std::endl;
 19     std::cout << first << std::endl;
 20     std::cout << second << std::endl;
 21 
 22     return 0;
 23 }

And I'm compiling using "g++ -o formatname formatname.cpp" only to get the following error:

formatname.cpp: In function ‘int main()’:
formatname.cpp:11: error: invalid conversion from ‘const char*’ to ‘char’
formatname.cpp:11: error: initializing argument 2 of ‘std::basic_string<_CharT, _Traits, _Alloc>::basic_string(typename _Alloc::rebind<_CharT>::other::size_type, _CharT, const _Alloc&) [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>]’
formatname.cpp:13: error: invalid conversion from ‘const char*’ to ‘char’
formatname.cpp:13: error: initializing argument 2 of ‘std::basic_string<_CharT, _Traits, _Alloc>::basic_string(typename _Alloc::rebind<_CharT>::other::size_type, _CharT, const _Alloc&) [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>]’

Any idea what's up? I copied the example line for line (aside from comments).

[vlad from moscow]

You set incorrect arguments for std::string constructor. In statement

const std::string spaces(greeting.size(), " ");

Instead of string literal " " a simple character shall be. That is the correct statement looks like

const std::string spaces(greeting.size(), ' ' );

[Shlomo]

Ahhh--thank you vlad. Didn't realize there was a different between double and single quote marks