can c_str return null

Since you only need that new behavior for interacting with that legacy libr...

Since you only need that new behavior for interacting with that legacy library and not in all code (for example strlen() will break if you pass a.

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Since c_str() is contracted to return a null terminated string it can never...

Since c_str() is contracted to return a null terminated string it can never return NULL. The correct way to test for an empty string is indeed.

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No. Since c_str returns a pointer p to a null-terminated array of character...

No. Since c_str returns a pointer p to a null-terminated array of characters, there must be some value i >= 0 such that p[i] == '\0', and thus p.

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You can't construct a std::string object without a corresponding valid...

You can't construct a std::string object without a corresponding valid C-string. std::string() is A null pointer with const char* type is a non-existent string. If an empty string's c_str returned nullptr, then this would not be valid.

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string ensure it remains true, and all public member functions can rely on ...

string ensure it remains true, and all public member functions can rely on it being true). An implementation of c_str cannot return a pointer to new array, The requirement is the c_str must return a null terminated cstring.

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s[2] == '\0' s[3] == '\0' We know that s[1] HAS to be a...

s[2] == '\0' s[3] == '\0' We know that s[1] HAS to be a null character (because::c_str() guarantees that its return string will be NULL-terminated).

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most std::string implementations just keep an extra char allocated for the ...

most std::string implementations just keep an extra char allocated for the NULL termination so they can return a pointer to their internal buffer.

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That is, you can't pass back a NULL construct with a string type. You ...

That is, you can't pass back a NULL construct with a string type. You can return NULL, but if the calling function tried to print it, then you're . (it worked) { return std::char_traits::copy(returnValue, someValue.c_str(),  What does the c_str() function do exactl.

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Returns a pointer to an array that contains a null-terminated sequence of (...

Returns a pointer to an array that contains a null-terminated sequence of (cstr, str.c_str()); // cstr now contains a c-string copy of str char * p = std::strtok (cstr.

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This includes the null-terminated byte string (NTBS) returned by the c_str(...

This includes the null-terminated byte string (NTBS) returned by the c_str() (This compliant solution does assume that displayString does not.

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Returns a pointer to a null-terminated character array with data equivalent...

Returns a pointer to a null-terminated character array with data equivalent to string if the string object does not contain other null characters.

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If I recall, the standard allows string::c_str() to return pretty much . al...

If I recall, the standard allows string::c_str() to return pretty much . always be wide enough to store the null at end. c_str(), by itself, can still do.

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AtString will automatically call c_str() in most situations and so can be P...

AtString will automatically call c_str() in most situations and so can be Passing NULL to the AtString constructor is valid and c_str() will then return NULL.

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You can have as many null characters as you like and they do not affect is ...

You can have as many null characters as you like and they do not affect is used as a null-terminated character string, when c_str is called; but.

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A valid C string requires the presence of a terminating "null characte...

A valid C string requires the presence of a terminating "null character" (a character char s1[20]; // Character array - can hold a C string, but is not yet a valid C . The string class provides a method called c_str() that returns a pointer to a char.

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