Using push_back on a vector of strings - C++
Solution 1
no need for strcpy for a single character.
string str ("x");
str[0] = main_string[0];
vector_string.push_back(str);
Solution 2
You can also initialize with one character like this.
string str(1,main_string[0]);
vector_string.push_back(str);
Solution 3
You can add the character directly via an appropriate string constructor:
vector_string.push_back(string(1, main_string[0]));
EDIT: Removed alternate solution after realising it duplicates @Tim's.
Comments
-
Sriram about 4 years
I am trying to use
push_back
on a vector of strings in C++. How can I push a single character on to the vector? Currently, I have tried the following, all without success:- Initialized a string (tried to) with the character.
Code
string str(main_string[0]); vector_string.push_back(str);
- Tried to invoke strcpy and thus copy contents. Const-ness seems to get in the way.
Code
string str; strcpy(main_string[0], str.c_str()); vector_string.push_back(str);
Any more suggestions/ideas are most welcome.
Edit: The error logs are as follows:
test_push.C: In function ‘void test_push(std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >&, std::string)’: test_push.C:50: error: no matching function for call to ‘std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char&)’ /usr/lib/gcc/i586-redhat-linux/4.4.1/../../../../include/c++/4.4.1/bits/basic_string.tcc:220: note: candidates are: 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>] /usr/lib/gcc/i586-redhat-linux/4.4.1/../../../../include/c++/4.4.1/bits/basic_string.tcc:213: note: std::basic_string<_CharT, _Traits, _Alloc>::basic_string(const _CharT*, const _Alloc&) [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>] <near match> /usr/lib/gcc/i586-redhat-linux/4.4.1/../../../../include/c++/4.4.1/bits/basic_string.tcc:206: note: std::basic_string<_CharT, _Traits, _Alloc>::basic_string(const _CharT*, typename _Alloc::rebind<_CharT>::other::size_type, const _Alloc&) [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>] /usr/lib/gcc/i586-redhat-linux/4.4.1/../../../../include/c++/4.4.1/bits/basic_string.tcc:194: note: std::basic_string<_CharT, _Traits, _Alloc>::basic_string(const std::basic_string<_CharT, _Traits, _Alloc>&, typename _Alloc::rebind<_CharT>::other::size_type, typename _Alloc::rebind<_CharT>::other::size_type, const _Alloc&) [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>] /usr/lib/gcc/i586-redhat-linux/4.4.1/../../../../include/c++/4.4.1/bits/basic_string.tcc:184: note: std::basic_string<_CharT, _Traits, _Alloc>::basic_string(const std::basic_string<_CharT, _Traits, _Alloc>&, typename _Alloc::rebind<_CharT>::other::size_type, typename _Alloc::rebind<_CharT>::other::size_type) [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>] /usr/lib/gcc/i586-redhat-linux/4.4.1/../../../../include/c++/4.4.1/bits/basic_string.tcc:170: note: std::basic_string<_CharT, _Traits, _Alloc>::basic_string(const std::basic_string<_CharT, _Traits, _Alloc>&) [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>] /usr/lib/gcc/i586-redhat-linux/4.4.1/../../../../include/c++/4.4.1/bits/basic_string.tcc:178: note: std::basic_string<_CharT, _Traits, _Alloc>::basic_string(const _Alloc&) [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>] /usr/lib/gcc/i586-redhat-linux/4.4.1/../../../../include/c++/4.4.1/bits/basic_string.h:2147: note: std::basic_string<_CharT, _Traits, _Alloc>::basic_string() [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>] test_push.C:61: error: conversion from ‘char’ to non-scalar type ‘std::string’ requested test_push:90: error: no matching function for call to ‘std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char&)’ /usr/lib/gcc/i586-redhat-linux/4.4.1/../../../../include/c++/4.4.1/bits/basic_string.tcc:220: note: candidates are: 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>] /usr/lib/gcc/i586-redhat-linux/4.4.1/../../../../include/c++/4.4.1/bits/basic_string.tcc:213: note: std::basic_string<_CharT, _Traits, _Alloc>::basic_string(const _CharT*, const _Alloc&) [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>] <near match> /usr/lib/gcc/i586-redhat-linux/4.4.1/../../../../include/c++/4.4.1/bits/basic_string.tcc:206: note: std::basic_string<_CharT, _Traits, _Alloc>::basic_string(const _CharT*, typename _Alloc::rebind<_CharT>::other::size_type, const _Alloc&) [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>]
More info: In this function, either the entire string or just the first letter is pushed in to the vector based on its contents. So, in a way, I am looking for some function that converts a
char
into a C++ stylestd::string
(to make it acceptable to a vector).Thanks,
Sriram