standard-library

According to this reference entry for operator new ( http://www.cplusplus.com/reference/std/new/operator%20new/ ) : Global dynamic storage operator functions are special in the standard library: All three versions of operator new are declared in the global namespace, not in the std namespace. The first and second versions are implicitly declared in every translation unit of a C++ program: The header does not need to be included for them to be present. This seems to me to imply that the third version of operator new (placement new) is not implicitly declared in every translation unit of a C++

I know it is a common issue, but looking for references and other material I don't find a clear answer to this question. Consider the following code: #include <string> // ... // in a method std::string a = "Hello "; std::string b = "World"; std::string c = a + b; The compiler tells me it cannot find an overloaded operator for char[dim] . Does it mean that in the string there is not a + operator? But in several examples there is a situation like this one. If this is not the correct way to concat more strings, what is the best way? Your code, as written, works. You’re probably trying to achieve

Go's standard library does not have a function solely intended to check if a file exists or not (like Python's os.path.exists ). What is the idiomatic way to do it? Sridhar Ratnakumar To check if a file doesn't exist, equivalent to Python's if not os.path.exists(filename) : if _, err := os.Stat("/path/to/whatever"); os.IsNotExist(err) { // path/to/whatever does not exist } To check if a file exists, equivalent to Python's if os.path.exists(filename) : Edited: per recent comments if _, err := os.Stat("/path/to/whatever"); err == nil { // path/to/whatever exists } else if os.IsNotExist(err) { //

I set up CDT for eclipse and wrote a simple hello world C program: #include <stdio.h> int main(void){ puts("Hello, world."); return 0; } The program builds and runs correctly, but eclipse keeps showing this yellow question mark by the side of inclusion statement that says "Unresolved inclusion: <stdio.h>" when I put mouse over it. It doesn't affect running of the program but I find it rather annoying. Does anyone have any idea how to remove it ? The compiler Eclipse is using is able to resolve the symbols just fine, so the code will compile fine. But the code-completion/preprocessor Eclipse is

What are the reasons for the existence of std::decay ? In what situations is std::decay useful? <joke>It's obviously used to decay radioactive std::atomic types into non-radioactive ones.</joke> N2609 is the paper that proposed std::decay . The paper explains: Simply put, decay<T>::type is the identity type-transformation except if T is an array type or a reference to a function type. In those cases the decay<T>::type yields a pointer or a pointer to a function, respectively. The motivating example is C++03 std::make_pair : template <class T1, class T2> inline pair<T1,T2> make_pair(T1 x, T2 y)

I am writing a custom console program. And I want to make it look like an actual one. So I want to bind some actions with keypress events. For example when the up arrow is pressed previously executed commands should be shown to the user. I know about SDL. But I think that it's not a standard library, is it ?? If there is other alternative of it, that included in standard CPP library, please let me know. Thanks. You won't find anything in the standard library for that. It's all Platform-dependent. In Windows, you have functions like GetAsyncKeyState to get the state of a key on the keyboard for