Book Image

C++ High Performance

By : Björn Andrist, Viktor Sehr
5 (1)
Book Image

C++ High Performance

5 (1)
By: Björn Andrist, Viktor Sehr

Overview of this book

C++ is a highly portable language and can be used to write both large-scale applications and performance-critical code. It has evolved over the last few years to become a modern and expressive language. This book will guide you through optimizing the performance of your C++ apps by allowing them to run faster and consume fewer resources on the device they're running on without compromising the readability of your code base. The book begins by helping you measure and identify bottlenecks in a C++ code base. It then moves on by teaching you how to use modern C++ constructs and techniques. You'll see how this affects the way you write code. Next, you'll see the importance of data structure optimization and memory management, and how it can be used efficiently with respect to CPU caches. After that, you'll see how STL algorithm and composable Range V3 should be used to both achieve faster execution and more readable code, followed by how to use STL containers and how to write your own specialized iterators. Moving on, you’ll get hands-on experience in making use of modern C++ metaprogramming and reflection to reduce boilerplate code as well as in working with proxy objects to perform optimizations under the hood. After that, you’ll learn concurrent programming and understand lock-free data structures. The book ends with an overview of parallel algorithms using STL execution policies, Boost Compute, and OpenCL to utilize both the CPU and the GPU.
Table of Contents (13 chapters)

Const propagation for pointers

A common mistake when writing const-correct code in C++ is that a const initialized object can still manipulate the values that member pointers points at. The following example illustrates the problem:

class Foo {
Foo(int* ptr) : ptr_{ptr} {}
auto set_ptr_val(int v) const {
*ptr_ = v; // Compiles despite function being declared const!
int* ptr_{};

auto main() -> int {
const auto foo = Foo{};

Although the function set_ptr_val() is mutating the int value, it's valid to declared it const since the pointer ptr_ itself is not mutated, only the int object that the pointer is pointing at.

In order to prevent this in a readable way, a wrapper called std::experimental::propagate_const has been added to the std library extensions (included in, as of the time of writing this, the latest versions of...