Code coverage macro

#include <iostream>

struct CoverageNode
{
    CoverageNode(const int in_line)
        : line(in_line)
    {
        if (first)
        {
            next = first;
        }
        first = this;
    }

    int line;
    bool covered;
    CoverageNode *next;

    static CoverageNode *first;
};

CoverageNode *CoverageNode::first;

template<class Function>
void for_each_coverage(const Function &function)
{
    for (const auto *node = CoverageNode::first; node; node = node->next)
    {
        function(*node);
    }
}

template<int line>
struct LineCoverage
{
    static CoverageNode node;
};

template<int line>
CoverageNode LineCoverage<line>::node = CoverageNode(line);

#define BRANCH() LineCoverage<__LINE__>::node.covered = true

void foo(const bool b)
{
    if (b)
        BRANCH();
    else
        BRANCH();
}

int main()
{
    foo(false);

    for_each_coverage([] (const CoverageNode &node) {
        std::cout << node.line << " " << node.covered << std::endl;
    });
}