declaration

std::is_function is specialized for types which have signature similar to: int(int) & see here: std::is_function But this is neither a pointer to a member method, which signature could be: int(T::*)(int) & Nor it can be a reference to a function: int (&)(int) So what is this strange signature? It's a function type which only exists in the type system. It cannot ever be created. But this is neither a pointer to a member method, which signature could be: int(T::*)(int) & It's this, without the pointer. The type system allows you to describe that as a type. #include <type_traits> struct T { };

I have created an XML file using python. But the XML declaration has only version info. How can I include encoding with XML declaration like: <?xml version="1.0" encoding="UTF-8"?> >>> from xml.dom.minidom import Document >>> a=Document() >>> a.toprettyxml(encoding="utf-8") '<?xml version="1.0" encoding="utf-8"?>\n' or >>> a.toxml(encoding="utf-8") '<?xml version="1.0" encoding="utf-8"?>' you can set the encoding for the document.writexml() function in the same way. 来源： https://stackoverflow.com/questions/2597622/encoding-in-xml-declaration-python

The ANSI C grammar from -link- give me the following rules for array declarations: (1) | direct_declarator '[' type_qualifier_list assignment_expression ']' (2) | direct_declarator '[' type_qualifier_list ']' (3) | direct_declarator '[' assignment_expression ']' (4) | direct_declarator '[' STATIC type_qualifier_list assignment_expression ']' (5) | direct_declarator '[' type_qualifier_list STATIC assignment_expression ']' (6) | direct_declarator '[' type_qualifier_list '*' ']' (7) | direct_declarator '[' '*' ']' (8) | direct_declarator '[' ']' Now I have a some questions about these: Can I use

This code works: std::ifstream f(mapFilename.c_str()); std::string s = std::string(std::istreambuf_iterator<char>(f), std::istreambuf_iterator<char>()); ParseGameState(s); Whereby mapFilename is an std::string and void ParseGameState(const std::string&); . And this does not: std::ifstream f(mapFilename.c_str()); std::string s(std::istreambuf_iterator<char>(f), std::istreambuf_iterator<char>()); ParseGameState(s); This is the error: game.cpp: In member function ‘int Game::LoadMapFromFile(const std::string&)’: game.cpp:423: error: no matching function for call to ‘ParseGameState(std::string (&)

Why do classes in C++ have to declare their private functions? Has it actual technical reasons (what is its role at compile time) or is it simply for consistency's sake? I asked why private functions had to be declared at all, as they don't add anything (neither object size nor vtable entry) for other translation units to know If you think about it, this is similar to declaring some functions static in a file. It's not visible from the outside, but it is important for the compiler itself. The compiler wants to know the signature of the function before it can use it. That's why you declare

I have an object declared in my app delegate: @interface MyAppDelegate : NSObject <UIApplicationDelegate> { ClassName *className; } In another class, I include the app delegate: #import "MyAppDelegate.h" @implementation AnotherClass -(void)doMethod { [className doClassNameMethod]; } This fails at compile time due to className being undeclared. Shouldn't it be accessible, since I've included the MyAppDelegate, where className is declared? I need AnotherClass.doMethod to be accessing the same instance that is created in MyAppDelegate. Any help on this would be most appreciated. Thanks. To access

What is the difference between declaration and prototype in C? In which situations they are called declarations and in which prototypes? TL;DR; All prototypes are declarations, but not all declarations are prototypes. Declaration is the generic terminology used in the standards, prototype is more specific. Quoting C11 , chapter §6.7 A declaration specifies the interpretation and attributes of a set of identifiers. [...] and from §6.7.6, Each declarator declares one identifier, and asserts that when an operand of the same form as the declarator appears in an expression, it designates a function