libcruft-util/posix/except.hpp

82 lines
2.0 KiB
C++

/*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* Copyright 2010-2018
* Danny Robson <danny@nerdcruft.net>
*/
#pragma once
#include <functional>
#include <stdexcept>
namespace cruft::posix {
/// An exception class used for reporting errors signalled by errno.
///
/// Ideally this would be named `errno' but that symbol is permitted to
/// be a macro and significantly complicates symbol resolution either way.
class error : public std::exception {
public:
explicit error (int code);
error ();
int code (void) const;
static int last_code (void);
template <typename FunctionT, typename ...Args>
static auto
try_call (FunctionT &&func, Args&& ...args)
{
return try_value (
std::invoke (
std::forward<FunctionT> (func),
std::forward<Args> (args)...
)
);
}
static void try_code (void);
static void try_code (int code);
static void throw_code [[gnu::noreturn]] (void);
static void throw_code [[gnu::noreturn]] (int code);
virtual const char* what (void) const noexcept final override;
template <typename T>
static T try_value (T value)
{
if (value < 0)
throw_code ();
return value;
}
private:
int const m_code;
};
template <int CodeV>
struct error_code : public error {
error_code ():
error (CodeV)
{ ; }
};
class eai : public std::runtime_error {
public:
explicit eai (int code);
int code (void) const;
static void try_code (int);
static void throw_code [[gnu::noreturn]] (int);
private:
int m_code;
};
};