Anything related to `c_str` method of class `std::basic_string` of C++ standard library.
Anything related to c_str method of class std::basic_string of C++ standard library.
See documentation of c_str on CPPreference.com.
Questions tagged [c-str]
73 questions
2
votes
1 answer
Boost.Program_Options: Why does options_description_easy_init::operator() not have an overload for std::string?
Consider this MCVE:
#include
#include
#include
2
votes
2 answers
Using String c_str() to return char*
I am working on some legacy code where I have to make some changes in the cpp file.The cpp file contains entire code in extern "c" block -
I updated a function that returns a char* .The code looks something like func1() below.
Since I use…
Anil
- 111
- 6
2
votes
2 answers
Printf and C++ strings
So I have the following code:
#include
#include
#include
using namespace std;
int main() {
vector strs;
strs.push_back("happy");
const string& a1 = strs[0];
strs.push_back("birthday");
…
Bob Sacamano
- 699
- 15
- 39
2
votes
2 answers
Value equality of c_str == string vs c_str == c_str
I'm trying to compare libpqxx c_str values.
If I try to compare them directly, result1[0][0].c_str() == result2[0][0].c_str(), for example, they do not return true when they have the same string values. The only way to compare them properly is to…
user1382306
2
votes
4 answers
What does eof() returns?
Here is the code:
string fname = "/home/jack/example.csv";
ifstream csvin(fname.c_str());
if (csvin.eof()) {
do_something;
}
My question is: In what case eof() returns true. I have the following options:
File does not exist.
File is…
Roman
- 124,451
- 167
- 349
- 456
2
votes
3 answers
C++ c_str doesn't return entire string
I've tried the following code with both normal ifstreams and the current boost:iostream I'm using, both have the same result.
It is intended to load a file from physfs into memory then pass it to a handler to process (eg Image, audio or data).…
Simon Moles
- 359
- 1
- 5
- 11
2
votes
2 answers
C++ STL: will c_str() be changed when creating const copy of std::string?
This is question about difference between STL implementations in handling const copy of std::string. I have such short test, which does 2 const copies and prints addresses returned by c_str():
#include
#include
using namespace…
osgx
- 90,338
- 53
- 357
- 513
2
votes
5 answers
C++ toString() with sprintf()
With C++ I am trying to implement a toString() function for my class:
void ClassName::toString(string& returnString)
{
sprintf(returnString.c_str(), "Position: (%f, %f, %f)\n", position.x, position.y, position.y);
}
However I keep getting this…
CodeKingPlusPlus
- 15,383
- 51
- 135
- 216
2
votes
3 answers
c++ c_str adding strange characters to the end of the string
let me first thank you for taking the time to read this.
I'm trying to read a file in c++. Currently I have a method that allows the user to select a file in explorer and returns this as an 'std::string'. I then have to open this file, but the…
planty182
- 57
- 1
- 9
1
vote
0 answers
fstream and c_str() : c_str is not working
I have been recently working on a program and i tried to use System::String^ to use it for an ofstream file...
I always get an Error...
Note This is a Form so it is a Header File.
This is my Code...(one part)
System::String^ txtPath;
#pragma…
user1296520
- 11
- 1
1
vote
0 answers
Use of c_str() for wstrings in c++
When I have a:
std::string s
I can do:
s.c_str()
to convert it to a char*. As I understand it only adds a '\0' to the end of s.
Can I then conclude that just adding '\0' converts a string to a char*?
Is doing something like that converting it to…
user3443063
- 1,455
- 4
- 23
- 37
1
vote
1 answer
Unexpected behavior when converting a character array to a string
So I have this simple class, it takes a character array and parses it into a JSON object. It then stores that object internally and provides a getter.
class JSONContainer {
public:
explicit JSONContainer(const char* const json) {
…
Tyler Weiss
- 139
- 1
- 15
1
vote
0 answers
Weird behaviour of string size function or am I doing something wrong?
I am getting the wrong std::string size value.
statsd_link* statsd_init(std::string& host, int port) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG,
"statsd_init print data to %s:%d and length: %ld, %ld\n",
…
Shravan40
- 8,922
- 6
- 28
- 48
1
vote
1 answer
format float in C++ mfc
I used VS2010 to build a MFC program in windows 7. I want to format the float data in the report generated.
I have tried to use %f but the "%f" is showed in the report.
CString m_Iwork_min;
struct m_report_info;
m_Iwork_min =…
Bill
- 33
- 7
1
vote
1 answer
After recompiling our FORTRAN-code and using it in C++ our system() or c_str() command don`t work properly
Hi I have a big problem: We created a program in C++/Qt 4.8.4 /Qt Creator 2.8.1 years ago that while executing runs another executable (written and compiled in FORTRAN). Everything worked well.
We recompiled our Fortran-Code with the new version of…
user3443063
- 1,455
- 4
- 23
- 37