You can replace cout by a stringstream. std::stringstream buffer; buffer << “Text” << std::endl; You can access the string using buffer.str(). To use stringstream you need to use the following libraries: #include <string> #include <iostream> #include <sstream>
#include <sstream> // st is input string int result; stringstream(st) >> result;
Yes you can have embedded nulls in your std::string. Example: std::string s; s.push_back(‘\0’); s.push_back(‘a’); assert(s.length() == 2); Note: std::string‘s c_str() member will always append a null character to the returned char buffer; However, std::string‘s data() member may or may not append a null character to the returned char buffer. Be careful of operator+= One thing … Read more
In addition to @lubgr’s answer, the paper char8_t backward compatibility remediation (P1423) discusses several ways how to make std::string with char8_t character arrays. Basically the idea is that you can cast the u8 char array into a “normal” char array to get the same behaviour as C++17 and before, you just have to be a … Read more
C++14 No; you can depend on it. In 21.4.5.2 (or [string.access]) we can find: Returns: *(begin() + pos) if pos < size(). Otherwise, returns a reference to an object of type charT with value charT(), where modifying the object leads to undefined behavior. In other words, when pos == size() (which is true when both … Read more
You can use a Json::Writer to do exactly this, since I assume you want to save it somewhere so you don’t want human readable output, your best bet would be to use a Json::FastWriter and then you can call the write method with the parameter of your Json::Value (ie. your root) and then that simply … Read more
Because it is not initialized, it is the default constructor that is called. Then : empty string constructor (default constructor) : Constructs an empty string, with a length of zero characters. Take a look : http://www.cplusplus.com/reference/string/string/string/ EDIT : As stated in C++11, §21.4.2/1 : Effects: Constructs an object of class basic_string. The postconditions of this … Read more
The standard does not specify a specialization of std::atomic<std::string>, so the generic template <typename T> std::atomic<T> applies. 29.5 [atomics.types.generic] p1 states: There is a generic class template atomic. The type of the template argument T shall be trivially copyable (3.9). There is no statement that the implementation must diagnose violations of this requirement. So either … Read more
or using the stringstreams: #include <sstream> #include <iomanip> std::stringstream ss; ss << std::setw(10) << std::setfill(‘0’) << i; std::string s = ss.str(); I compiled the information I found on arachnoid.com because I like the type-safe way of iostreams more. Besides, you can equally use this code on any other output stream.
Look at the documentation string::find std::string s = “hell[o”; if (s.find(‘[‘) != std::string::npos) ; // found else ; // not found