Alex

Development Environment and C++ Basics (Lecture 2)

• C++ is of course a compiled language
• The compilation first makes an object file, which is then linked to shared libraries
• CMake is commonly used to remove a lot of the boilerplate required for compiling C++ programs
  • It is used to generate makefiles to automatically build and test code
• CMakeLists.txt is where you would store your build script

cmake_minimum_required(VERSION 3.0)
project(Demo1)
add_executable(Demo1 demo1.cpp)

• Above is a minimal working example for a demo project
• CMake will generate makefiles that you can run with make

Namespaces

• Namespaces provide a scope to the identifiers (types, functions, variables etc.) inside it; used to organise code into logical groupings and prevent naming collisions

namespace someNamespace {
  double value = 3.14;
}

int main() {
  std::print("Value: {}", someNamespace::value)
  return 0
}

• You can also specify using namespace someNamespace to make everything in that namespace appear as if it was in the global namespace, helpful to remove syntactic cluttering
• C++ has pass by value semantics by default, we can make it pass by reference by using &, e.g. double sqrt(double& y)
  • We can use double const& y to promise that the argument isn’t changed