File Extensions

Source files should use .cpp
Header files should use .hpp

Because we a mixed C/C++ project, it is helpful to know which header files we can use in a C file. Therefore, a C header should have a different extension than a C++ header.

.hpp is chosen because it easily attributed to .cpp files.

From the Boost FAQ:

File extensions communicate the "type" of the file, both to humans and to computer programs. The '.h' extension is used for C header files, and therefore communicates the wrong thing about C++ header files... Using '.hpp' unambiguously identifies it as C++ header file, and works well in actual practice. (Rainer Deyke)

Whitespace

We use tabs to be consistent with our C code.

Because we use tabs, we can’t use partial indents.
We don’t want to have a ton of horizontal white space making our lines longer than it has to be.

Classes will not have an indent before public, protected and private

// Bad
class MyClass {
  public:
    MyClass();
    ~MyClass();
  private:
    int count;
};

// Good
class MyClass {
public:
  MyClass();
  ~MyClass();
private:
  int count;
};

Namespaces will not cause a level of indentation

namespace pbs {
// Bad
  int add(int x, int y);
// Good
int add(int x, int y);
}

Names and Orders of Includes

pbs_config.h if needed
System and STL headers
pbs headers

Some good things to keep in mind

Casting

Do not use C-style casts; instead use C++ style casts.

// Bad
int *p = (int *)malloc(sizeof(int));
// Good
int *p = static_cast<int *>(malloc(sizeof(int)));

Note: Void pointers can't be assigned to non-void pointers without a cast.

Use `const char *` whenever possible

If you're not changing a char * argument, use const in the function definition

// Bad
void
logmsg(int sev, char *msg)
{
  printf("%d\t%s\n", sev, msg);
  return;
}
// Good
void
logmsg(int sev, const char *msg)
{
  printf("%d\t%s\n", sev, msg);
  return;
}

Prefer `nullptr` to `NULL`

NULL is often just defined 0, nullptr is a pointer type pointing to the address 0x0.

// Bad
int *p = NULL;
// Good
int *p = nullptr;

auto is awesome

A lot of types can be very long strings, such as classes with templates. auto lets you save some typing by deducing the type from the right-hand-side.

// bad
std::vector<MyClass> list = std::vector<MyClass>();
// good
auto list2 = std::vector<MyClass>();

Namespaces

Using using namespace <name> is not a good idea, as it can pollute the global namespace. Instead, use the namespace prefix.

// Bad
using namespace std;
auto vec = vector<int>();
// Good
auto vec = std::vector<int>();

If you’re in the pbs namespace, don’t create another namespace prefixed with pbs_

// Bad
namespace pbs {
namespace pbs_util {
int count_spaces(const char *);
}
}
int spaces = pbs::pbs_util::count_spaces("    ");

// Good
namespace pbs{
namespace util {
int count_spaces(const char *);
}
}
int spaces = pbs::util::count_spaces("    ");

Unique Pointers

You can find an example of unique pointers here: Unique Pointer Example

Inheritance/Polymorphism

You can find an example of these OOP features here: Inheritance/Polymorphism example

C++ Coding Standards