Re: Mimicking Javas static class initializer in C++

From:

Jeff Schwab <jeff@schwabcenter.com>

Newsgroups:

comp.lang.c++

Date:

Mon, 27 Oct 2008 18:54:35 -0400

Message-ID:

<eMednUI8UrI225vUnZ2dnUVZ_sbinZ2d@giganews.com>

Ian Collins wrote:

Jeff Schwab wrote:

Andreas Wollschlaeger wrote:

Lars Tetzlaff schrieb:

xx.h:

#include <vector>

class Thing
{
};

class Foo
{
private:
    static std::vector<Thing> xx;
    static class MyVector : public std::vector<Thing*>{ public:
MyVector(); } yy;
};

xx.cpp:

#include <xx.h>

std::vector<Thing> Foo::xx( 42 );
Foo::MyVector::MyVector()
{
    for( int i = 0; i<42; ++i ) {
    yy.push_back( new Thing() );
    }
}

Foo::MyVector Foo::yy;

Well, great, this was just what i have been looking for: encapsulating
the statics initialization in some inner class and its default
constructor - much more elegant and "cplusplusish" than my previous
attempt :-) Tx to you and the other folks, added me some more insight
to C++ this evening!

I can see why that solution would look nice to a Java developer, but in
general, it's a bad idea to derive your own classes from the standard
ones; it is especially non-c++ish.

Unless you make the inheritance private, which would work equally well here:

static class MyVector : std::vector<Thing*>
{
public:
MyVector();
} yy;

True that. :)