stdstring

Is it possible... when the debugger is stopped at a breakpoint, to modify the value of a std::string variable without resorting to hacks like tweaking the memory image of the current buffer? e.g. something like "set var mystring="hello world" ? Try this (tested and works for me): call mystring.assign("hello world") The key is that instead of modifying memory directly, you call the object's functions to change its state. It so happens that std::basic_string has a member function called assign which does the job. 来源： https://stackoverflow.com/questions/2502314/setting-an-stdstring-variable-value

Initializing std::string from a NULL char pointer is undefined behaviour, I believe. So, here are alternative versions of a constructor, where mStdString is a member variable of type std::string : void MyClass::MyClass(const char *cstr) : mStdString( cstr ? cstr : "") {} void MyClass::MyClass(const char *cstr) : mStdString(cstr ? std::string(cstr) : std::string()) {} void MyClass::MyClass(const char *cstr) { if (cstr) mStdString = cstr; // else keep default-constructed mStdString } Edit, constructor declaration inside class MyClass : MyClass(const char *cstr = NULL); Which of these, or

Consider a scenario, where std::string is used to store a secret . Once it is consumed and is no longer needed, it would be good to cleanse it, i.e overwrite the memory that contained it, thus hiding the secret . std::string provides a function const char* data() returning a pointer to (since C++11) continous memory. Now, since the memory is continous and the variable will be destroyed right after the cleanse due to scope end, would it be safe to: char* modifiable = const_cast<char*>(secretString.data()); OpenSSL_cleanse(modifiable, secretString.size()); According to standard quoted here: $5.2

I have a function which needs to encode strings, which needs to be able to accept 0x00 as a valid 'byte'. My program needs to check the length of the string, however if I pass in "\x00" to std::string the length() method returns 0. How can I get the actual length even if the string is a single null character? You're passing in an empty string. Use std::string(1, '\0') instead. Or std::string{ '\0' } (thanks, @zett42) std::string is perfectly capable of storing nulls. However, you have to be wary, as const char* is not, and you very briefly construct a const char* , from which you create the

I have the following cout statement. I use char arrays because I have to pass to vsnprintf to convert variable argument list and store in Msg . Is there any way we can get cout output to C++ std::string ? char Msg[100]; char appname1[100]; char appname2[100]; char appname3[100]; // I have some logic in function which some string is assigned to Msg. std::cout << Msg << " "<< appname1 <<":"<< appname2 << ":" << appname3 << " " << "!" << getpid() <<" " << "~" << pthread_self() << endl; Björn Pollex You can replace cout by a stringstream . std::stringstream buffer; buffer << "Text" << std::endl;

My company use some code like this: std::string(CT2CA(some_CString)).c_str() which I believe it converts a Unicode string (whose type is CString)into ANSI encoding, and this string is for a email's subject. However, header of the email (which includes the subject) indicates that the mail client should decode it as a unicode (this is how the original code does). Thus, some German chars like "ä ö ü" will not be properly displayed as the title. Is there anyway that I can put this header back to UTF8 and store into a std::string or const char*? I know there are a lot of smarter ways to do this,