drodil

#include <iostream>
#include <string>
#include <map>

class Mapleton {
public:
    // Returns a reference to static instance of this class
    // based on provided string identifier
    static Mapleton& instance(const std::string& id) {
        static std::map<std::string, Mapleton> instances;

drodil

#include <iostream>
#include <string>

class Singleton {
public:
    // Returns a reference to static instance of this class
    static Singleton& instance() {
        static Singleton instance;
        return instance;
    }

drodil

drodil

#include <vector>

std::size_t counter = 0;
std::mutex cout_mutex;
void foo()
{
    {
        std::lock_guard<std::mutex> lock(cout_mutex);
        std::cout << "T" << get_thread_id() << " increasing counter" << std::endl;
    }

drodil

T0 increasing counter
T1 increasing counter
==================
WARNING: ThreadSanitizer: data race (pid=4888)
  Write of size 8 at 0x0000011b4980 by thread T2:
    #0 foo() ??:? (a.out+0x4c521b)
    #1 void std::_Bind_simple<void (*())()>::_M_invoke<>(std::_Index_tuple<>) ??:? (a.out+0x4cbeb5)
    #2 std::_Bind_simple<void (*())()>::operator()() ??:? (a.out+0x4cbe48)
    #3 std::thread::_Impl<std::_Bind_simple<void (*())()> >::_M_run() ??:? (a.out+0x4cbaac)
    #4 std::this_thread::__sleep_for(std::chrono::duration<long, std::ratio<1l, 1l> >, std::chrono::duration<long, std::ratio<1l, 1000000000l> >) ??:? (libstdc++.so.6+0xb8c7f)

drodil

#include <iostream>

class BaseClass {
public:
    void say_hello() { 
        std::cout << "Hello";
    }
protected:
    void say_world() {
        std::cout << "world!";

drodil

// test_class.hpp
#include <iosfwd>

class TestClass {
public:
    TestClass() = default;
    void hello_to_stream(std::stringstream& ss) const noexcept;
};

drodil

#include <iostream>

class BaseOutputter {
public:
    static void set_prefix_message(const std::string& msg) { 
        prefix_message = msg;   
    }
    
protected:
    BaseOutputter() = default;

drodil

#include <iostream>
#include <bitset>
#include <type_traits>

namespace test {
// Allows ~ operator for any enum class in the same namespace
template<class Enum, class = typename std::enable_if<std::is_enum<Enum>::value, Enum>::type> 
inline Enum operator~(Enum a) {
	return static_cast<Enum>(~static_cast<typename std::underlying_type<Enum>::type>(a));
}

drodil

#include <thread>
#include <atomic>

std::size_t get_thread_id() noexcept {
    static std::atomic<std::size_t> thread_idx{0};
    thread_local std::size_t id = thread_idx;
    thread_idx++;
    return id;
}