Coding Patterns

Static variables for header-only releases

Note: As of v.10.1.1, this pattern is still used, but it is no longer needed. Method implementations are now in .cpp files, so the more conventional mechanism for initialising static variables would work fine.

---

Here is a sample of the pattern that we are using:

private:
    static std::shared_ptr<Reporter>& defaultReporter();

public:
    static std::shared_ptr<Reporter> getDefaultReporter();

    static void setDefaultReporter(const std::shared_ptr<Reporter>& reporter);

(See snippet source)

namespace ApprovalTests
{
    std::shared_ptr<Reporter>& DefaultReporterFactory::defaultReporter()
    {
        static std::shared_ptr<Reporter> reporter = std::make_shared<DiffReporter>();
        return reporter;
    }

    std::shared_ptr<Reporter> DefaultReporterFactory::getDefaultReporter()
    {
        return defaultReporter();
    }

    void
    DefaultReporterFactory::setDefaultReporter(const std::shared_ptr<Reporter>& reporter)
    {
        defaultReporter() = reporter;
    }
}

(See snippet source)

Note the use of the reference (&) on the return type of the private method, and the addition of a getter and setter method.