twoscomplement

// A C++11 constexpr implementation of xxhash32
// Jonathan Adamczewski / https://twitter.com/twoscomplement
// A reimplementation of code from https://github.com/Cyan4973/xxHash


// Foundation functions / commonly used patterns

// Read four chars and construct uint32_t (little endian)
constexpr uint32_t xxh_read32(const char* input)
{ 

twoscomplement

// CRC tables, generated at compile time using C++11 constexpr, C++14 utility library, variadic template, initializer list
// Compiled and tested using msvc 2015, gcc 6.2, and clang 3.9.0.
// clang requires -std=c++14 -ftemplate-depth=512

#include <stdint.h>
#include <utility>

template<typename T, T Poly>
struct CrcTable {
  static constexpr T Generate(T v, int r = 8) {

twoscomplement

// Generate CRC tables at compile time. With slices.
// Based on http://create.stephan-brumme.com/crc32/#slicing-by-8-overview
//
// C++11, C++14 utility library, constexpr, variadic templates, initializer lists. 
//
// Tested using gcc-6.2, clang-3.9.0, and latest msvc 2015 compilers.
// clang: -std=c++14 -ftemplate-depth=512
//
// @twoscomplement 2016-09-26

twoscomplement

/*
  todo.h

  TODO():
    A macro that will fire a static assert if compiled on or after 
    a specified date.


  Requires C++11 constexpr support.

twoscomplement

// TransientFuction: A light-weight alternative to std::function [C++11]
// Pass any callback - including capturing lambdas - cheaply and quickly as a 
// function argument
// 
// Based on: 
// https://deplinenoise.wordpress.com/2014/02/23/using-c11-capturing-lambdas-w-vanilla-c-api-functions/
//
//  - No instantiation of called function at each call site
//  - Simple to use - use TransientFunction<> as the function argument
//  - Low cost: cheap setup, one indirect function call to invoke

twoscomplement

/*
Watch as the OS rewrites my buggy program.

Compile with:
cl //Ox movoops.cpp

Output:
0f 28 01
xxxxxxxxxxxxxxx1
0f 10 01

twoscomplement

#include <random>
#include <stdlib.h>
#include <cstdint>
#include <limits>
#include <type_traits>
#include <algorithm>
#include <string>

namespace __detail {
  template<typename _UIntType, size_t __w,

twoscomplement

/*
ARRAY_SIZE(a)
A macro to compute the number of elements in an array a.

Features & considerations:
- Will not compile if a is not an array (error message is not elegant).
- Able to be used with non-const a.
- Happens to produce very few (false-positive) compile-time warnings with msvc 19 when 
  the result is used in signed and truncating arithmetic - unlike std::size()
  (see also https://t.co/NvhjvMUhA1)