rygorous

Why do compilers even bother with exploiting undefinedness signed overflow? And what are those
mysterious cases where it helps?

A lot of people (myself included) are against transforms that aggressively exploit undefined behavior, but
I think it's useful to know what compiler writers are accomplishing by this.

TL;DR: C doesn't work very well if int!=register width, but (for backwards compat) int is 32-bit on all
major 64-bit targets, and this causes quite hairy problems for code generation and optimization in some
fairly common cases. The signed overflow UB exploitation is an attempt to work around this.

ajdavis

#!/usr/bin/env python

import difflib
import subprocess
import shutil
import sys
from os import getcwd
from os.path import normpath, expanduser, join, exists

from git import Repo  # pip install gitpython

MaikKlein

#include <iostream>
#include <functional>
#include <string>
#include <numeric>
#include <array>
template<typename T,typename R>
struct match_struct{
  T t;
  std::function<R(T&&)> f;
};

sonOfRa

# Once done these will be defined:
#
# LIBSODIUM_FOUND
# LIBSODIUM_INCLUDE_DIRS
# LIBSODIUM_LIBRARIES
#

if(LIBSODIUM_INCLUDE_DIRS AND LIBSODIUM_LIBRARIES)
	set(LIBSODIUM_FOUND TRUE)
else()

dabrahams

#include <iostream>
#include <iomanip>
//
// Utilities
//

// RETURNS() is used to avoid writing boilerplate "->decltype(x) { return x; }" phrases.
//
// USAGE: auto function(<arguments>) RETURNS(<some-expression>);
//

jeetsukumaran

// Sample custom iterator.
// By perfectly.insane (http://www.dreamincode.net/forums/index.php?showuser=76558)
// From: http://www.dreamincode.net/forums/index.php?showtopic=58468

#include <iostream>
#include <vector>
#include <algorithm>
#include <iterator>
#include <cassert>