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
142
votes
6 answers
string c_str() vs. data()
I have read several places that the difference between c_str() and data() (in STL and other implementations) is that c_str() is always null terminated while data() is not.
As far as I have seen in actual implementations, they either do the same or…
leon
118
votes
7 answers
What is the lifetime of the result of std::string::c_str()?
In one of my programs, I have to interface with some legacy code that works with const char*.
Lets say I have a structure which looks like:
struct Foo
{
const char* server;
const char* name;
};
My higher-level application only deals with…
ereOn
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95
votes
7 answers
What is the use of the c_str() function?
I understand c_str converts a string, that may or may not be null-terminated, to a null-terminated string.
Is this true? Can you give some examples?
Amit Singh Tomar
- 8,380
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38
votes
4 answers
c_str() vs. data() when it comes to return type
After C++11, I thought of c_str() and data() equivalently.
C++17 introduces an overload for the latter, that returns a non-constant pointer (reference, which I am not sure if it's updated completely w.r.t. C++17):
const CharT* data() const; (1) …
gsamaras
- 71,951
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26
votes
3 answers
Difference in c_str function specification between C++03 and C++11
In the C++ reference of c_str() in std::string the following appears:
Return value
Pointer to the underlying character storage.
data()[i] == operator[](i) for every i in [0, size()) (until C++11)
data() + i == &operator[](i) for every i in [0,…
Chiel
- 6,006
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16
votes
3 answers
What's the difference between std::string::c_str and std::string::data?
Why would I ever want to call std::string::data() over std::string::c_str()? Surely there is some method to the standard's madness here...
fbrereto
- 35,429
- 19
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10
votes
1 answer
How can I create and pass a null-terminated array of C-strings (char**) in rust?
I'm playing around with a new init system with #![no_std] and extern crate rlibc and making syscalls with asm, and currently trying to not allocate memory either. So the scope of possible tools I have is limited.
I need to call the execve syscall,…
Ant Manelope
- 531
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8
votes
4 answers
Returning 'c_str' from a function
This is from a small library that I found online:
const char* GetHandStateBrief(const PostFlopState* state)
{
static std::ostringstream out;
// ... rest of the function ...
return out.str().c_str()
}
In my code I am doing this:
const…
user199421
- 1,850
- 2
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- 18
7
votes
3 answers
std::string::c_str & Null termination
I've read various descriptions of std::string::c_str including questions raised on SO over the years/decades,
I like this description for its clarity:
Returns a pointer to an array that contains a null-terminated sequence
of characters (i.e., a…
tuk
- 367
- 1
- 4
- 10
4
votes
5 answers
Setting a char array with c_str()?
char el[3] = myvector[1].c_str();
myvector[i] is a string with three letters in. Why does this error?
pighead10
- 4,155
- 10
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4
votes
2 answers
C++ Change working Directory from User Input
I'm designing a mock shell program, and I can't quite mimic the "cd" command. I've tried chdir(), but that wasn't working, so I moved on to trying to change the environmental variable "PWD="
Here's what I have, and I think this may be close.…
twsmale
- 139
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- 14
3
votes
4 answers
what is use of C_str() function in C/C++
Can anybody tell me what is the use of c_str() function in C/C++?.
In which case it is necessary to use it?.
sachin
- 311
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3
votes
6 answers
Store c_str() as char *
I'm trying to use the function with the following declaration:
extern int stem(struct stemmer * z, char * b, int k)1
I'm trying to pass a C++ string to it, so I thought I'd use the c_str() function. It returns const char *. When I try to pass it to…
muttley91
- 12,278
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3
votes
5 answers
.c_str() weirdness? Data changes without rhyme or reason?
I have this simple function:
const wchar_t *StringManager::GetWCharTStar(int stringId)
{
std::wstring originalString = StringManager::GetString(stringId);
const wchar_t *retStr = originalString.c_str();
return retStr;
}
At the second…
user189320
2
votes
1 answer
Is it safe to use std::string::c_str() to modify the underlying std::string?
I came across some code which has several instances of the bellow example:
std::string str = "This is my string";
char* ptr = const_cast(str.c_str());
ptr[5] = 'w';
ptr[6] = 'a';
In this simplified example there is an assignment of…
anastaciu
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