ctor-initializer

I've started trying out the C++11 standard and i found this question which describes how to call your ctor from another ctor in the same class to avoid having a init method or the like. Now i'm trying the same thing with code that looks like this: hpp: class Tokenizer { public: Tokenizer(); Tokenizer(std::stringstream *lines); virtual ~Tokenizer() {}; private: std::stringstream *lines; }; cpp: Tokenizer::Tokenizer() : expected('=') { } Tokenizer::Tokenizer(std::stringstream *lines) : Tokenizer(), lines(lines) { } But this is giving me the error: In constructor ‘config::Tokenizer::Tokenizer(std

This question already has an answer here: What is this weird colon-member (“ : ”) syntax in the constructor? 12 answers I am still learning C++ and trying to understand it. I was looking through some code and saw: point3(float X, float Y, float Z) : x(X), y(Y), z(Z) // <----- what is this used for { } What is the meaning of the "x(X), y(Y), z(Z)" sitting beside the constructor's parameters? It's a way of invoking the constructors of members of the point3 class. if x,y, and z are floats, then this is just a more efficient way of writing this point3( float X, float Y, float Z): { x = X; y = Y; z

So, the C++ standard requires that class members be initialized in the order in which they are declared in the class, rather than the order that they're mentioned in any constructor's initializer list. However, this doesn't imply anything about the order in which the arguments to those initializations are evaluated. I'm working with a system that frequently passes references to serialization objects around, and wondering if I can ensure that bits are read from it in the right order, independent of the order in which those bits get written into the object's fields. struct Foo { int a; double b;

Imagine I have a C++ class Foo and a class Bar which has to be created with a constructor in which a Foo pointer is passed, and this pointer is meant to remain immutable in the Bar instance lifecycle. What is the correct way of doing it? In fact, I thought I could write like the code below but it does not compile.. class Foo; class Bar { public: Foo * const foo; Bar(Foo* foo) { this->foo = foo; } }; class Foo { public: int a; }; Any suggestion is welcome. You need to do it in an initializer list: Bar(Foo* _foo) : foo(_foo) { } (Note that I renamed the incoming variable to avoid confusion.) I

class C { public: C() : arr({1,2,3}) //doesn't compile {} /* C() : arr{1,2,3} //doesn't compile either {} */ private: int arr[3]; }; I believe the reason is that arrays can be initialized only with = syntax, that is: int arr[3] = {1,3,4}; Questions How can I do what I want to do (that is, initialize an array in a constructor (not assigning elements in the body)). Is it even possible? Does the C++03 standard say anything special about initializing aggregates (including arrays) in ctor initializers? Or the invalidness of the above code is a corollary of some other rules? Do C++0x initializer

This question already has an answer here: What is this weird colon-member (“ : ”) syntax in the constructor? 12 answers What does the colon operator (":") do in this constructor? Is it equivalent to MyClass(m_classID = -1, m_userdata = 0); ? class MyClass { public: MyClass() : m_classID(-1), m_userdata(0) { } int m_classID; void *m_userdata; }; This is an initialization list , and is part of the constructor's implementation. The constructor's signature is: MyClass(); This means that the constructor can be called with no parameters. This makes it a default constructor , i.e., one which will be