SeanParent: Created page with " struct concept_t; struct vtable_t { void (destruct)(const concept_t&); concept_t (copy)(const concept_t&); void (print)(const concept_t&); }; struc..."

2013-01-15T06:13:54Z

Created page with " <nowiki> struct concept_t; struct vtable_t { void (*destruct)(const concept_t&); concept_t* (*copy)(const concept_t&); void (*print)(const concept_t&); }; struc..."

New page

<nowiki>
struct concept_t;

struct vtable_t {
void (*destruct)(const concept_t&);
concept_t* (*copy)(const concept_t&);
void (*print)(const concept_t&);
};

struct concept_t {
explicit concept_t(const vtable_t& x) : vtable_(&x) { }

void destruct() const { vtable_->destruct(*this); }
concept_t* copy() const { return vtable_->copy(*this); }
void print() const { vtable_->print(*this); }

const vtable_t* vtable_;
};

template <typename T>
struct model : concept_t {
explicit model(T& x) : concept_t(vtable_), data_(move(x)) { }
static void destruct(const concept_t& x) { static_cast<const model&>(x).~model(); }
static concept_t* copy(const concept_t& x) { return new model(static_cast<const model&>(x)); }
static void print(const concept_t& x) { cout << static_cast<const model&>(x).data_ << endl; }

static const vtable_t vtable_;

T data_;
};

template <typename T>
const vtable_t model<T>::vtable_ = {
&model::destruct,
&model::copy,
&model::print
};

class any {
public:
template <typename T>
any(T x) : object_(new model<T>(x)) { }
~any() { object_->destruct(); operator delete(static_cast<void*>(object_)); }
any(const any& x) : object_(x.object_->copy()) { }

friend inline void swap(any& x, any& y) { std::swap(x.object_, y.object_); }
any& operator=(const any& x) { any tmp(x); swap(*this, tmp); return *this; }

friend inline void print(const any& x) { x.object_->print(); }
private:
concept_t* object_;
};
</nowiki>

No virtual method "any" example - Revision history

SeanParent: Created page with " struct concept_t; struct vtable_t { void (*destruct)(const concept_t&); concept_t* (*copy)(const concept_t&); void (*print)(const concept_t&); }; struc..."

SeanParent: Created page with " struct concept_t; struct vtable_t { void (destruct)(const concept_t&); concept_t (copy)(const concept_t&); void (print)(const concept_t&); }; struc..."