Explicit virtual overrides

Use case

Catch typos when overriding virtual functions.

Explanation

override tells the compiler “we intend to override a base class function”. If we misspell the function name or get the signature wrong, we get a compile error (instead of silently creating a new function that never gets called).

Code

#include <iostream>

struct Analyzer {
  virtual void analyze() { std::cout << "Running base analyzer.\n"; }
};

struct MachOAnalyzer : Analyzer {
  void analyze() override { std::cout << "Running MachO analyzer.\n"; }

  // member function declared with 'override' does not override a base class member
  // void analize() override {}
};

int main() {
  MachOAnalyzer m;
  m.analyze();
  return 0;
}

View on GitHub.

Output

$ ./src/c++11/build/explicit-virtual-overrides
Running MachO analyzer.