TDD

Ref: Modern C++ Programming with Test-driven development by Jeff Langr

Effective Modern C++ by Scott Meyers

• Location 1620: C++ forbids reference to bits - auto in bool might be dangerous
• Location 1745: instead of C-style casting like (int)d, use static_cast<int> (d)
• Location 1863: uniform initializatio or braced initialization
  • int x(0);
  • int x= 0;
  • int x {0};
  • {} can be used anywhere. x(0) may not work in the class declaration. x=0 may not work for atomic
  • But {} checks type more strictly. Casting or type conversion will work with () or =
  • In overloading of constructors, it will prefer initialization_list
  • std::vector v1(10,20); 10 length vector with value of 20
  • std::vector v1{10,20}; a single vector with 2 elements of 10,20
• Location 2342: typedef => using

Best practice of C++11

• Pass by value vs pass by const address
  • f1(double dt) pass by value. Overhead of data copy. Data will not be changed
  • fi(double& dt) pass by address. Data can be changed
  • f1(const double& dt) or f1(double const& dt) pass by constant address. Recommended
  • Ref: https://softwareengineering.stackexchange.com/questions/372105/is-passing-arguments-as-const-references-premature-optimization
• Using unique pointer
  • Allocate dynamic array using new while delete is not required. Garbage collection
  • Not suitable for MPI communication. Use STL instead
  • Legacy pointer : requires delete

  int *x;
  x = new int (4);
  ...
  delete[] x;
  

  • std::unique_ptr : garbage collection. no delete

  std::unique_ptr<int[]> v {new int [4]}
  

  • Using make_unique (since -std=c++14) : garbage collection. no delete

  std::unique_ptr<int[]> w;
  w = std::make_unique<int[]>(4);
  

Valgrind

• Detection of uninitialized variables are done when the variables are compared
• Assigning uninitialized value is NOT detected

ctest from cmake

• ctest # run all tests - unit test, regression test, ...
• ctest -L some_test # run some_test among all tests
• ctest -LE some_test # run all tests but some_test
• ctest --timeout 1000 # each test will use time out 1000 sec
• ctest -R my_unit_test_01 # run one set named my_unit_test_01 among all tests
• ctest -VV -R my_unit_test_01 # run one set named my_unit_test01 among all tests. Higher verbosity. stdout will be shown in the screen output