nghttp2/src/template.h

151 lines
4.1 KiB
C++

/*
* nghttp2 - HTTP/2 C Library
*
* Copyright (c) 2015 Tatsuhiro Tsujikawa
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef TEMPLATE_H
#define TEMPLATE_H
#include "nghttp2_config.h"
#include <memory>
#include <array>
#include <functional>
namespace nghttp2 {
template <typename T, typename... U>
typename std::enable_if<!std::is_array<T>::value, std::unique_ptr<T>>::type
make_unique(U &&... u) {
return std::unique_ptr<T>(new T(std::forward<U>(u)...));
}
template <typename T>
typename std::enable_if<std::is_array<T>::value, std::unique_ptr<T>>::type
make_unique(size_t size) {
return std::unique_ptr<T>(new typename std::remove_extent<T>::type[size]());
}
template <typename T, typename... Rest>
std::array<T, sizeof...(Rest)+1> make_array(T &&t, Rest &&... rest) {
return std::array<T, sizeof...(Rest)+1>{
{std::forward<T>(t), std::forward<Rest>(rest)...}};
}
template <typename T, size_t N> constexpr size_t array_size(T (&)[N]) {
return N;
}
template <typename T, size_t N> constexpr size_t str_size(T (&)[N]) {
return N - 1;
}
// inspired by <http://blog.korfuri.fr/post/go-defer-in-cpp/>, but our
// template can take functions returning other than void.
template <typename F, typename... T> struct Defer {
Defer(F &&f, T &&... t)
: f(std::bind(std::forward<F>(f), std::forward<T>(t)...)) {}
Defer(Defer &&o) : f(std::move(o.f)) {}
~Defer() { f(); }
using ResultType = typename std::result_of<
typename std::decay<F>::type(typename std::decay<T>::type...)>::type;
std::function<ResultType()> f;
};
template <typename F, typename... T> Defer<F, T...> defer(F &&f, T &&... t) {
return Defer<F, T...>(std::forward<F>(f), std::forward<T>(t)...);
}
template <typename T, typename F> bool test_flags(T t, F flags) {
return (t & flags) == flags;
}
// doubly linked list of element T*. T must have field T *dlprev and
// T *dlnext, which point to previous element and next element in the
// list respectively.
template <typename T> struct DList {
DList() : head(nullptr), tail(nullptr) {}
DList(const DList &) = delete;
DList &operator=(const DList &) = delete;
DList(DList &&other) : head(other.head), tail(other.tail) {
other.head = other.tail = nullptr;
}
DList &operator=(DList &&other) {
if (this == &other) {
return *this;
}
head = other.head;
tail = other.tail;
other.head = other.tail = nullptr;
return *this;
}
void append(T *t) {
if (tail) {
tail->dlnext = t;
t->dlprev = tail;
tail = t;
return;
}
head = tail = t;
}
void remove(T *t) {
auto p = t->dlprev;
auto n = t->dlnext;
if (p) {
p->dlnext = n;
}
if (head == t) {
head = n;
}
if (n) {
n->dlprev = p;
}
if (tail == t) {
tail = p;
}
t->dlprev = t->dlnext = nullptr;
}
bool empty() const { return head == nullptr; }
T *head, *tail;
};
template <typename T> void dlist_delete_all(DList<T> &dl) {
for (auto e = dl.head; e;) {
auto next = e->dlnext;
delete e;
e = next;
}
}
} // namespace nghttp2
#endif // TEMPLATE_H