Here is a single header file only include solution for C++ unit testing:
https://gitlab.com/cppocl/unit_test_framework
Simple example of using it here, but it also has fixtures (setup and teardown), fail test on memory leak, fail test on performance (I've not seen this feature anywhere else).
#include "test/Test.hpp"
TEST(MyTest)
{
int a = 1;
int b = 2;
CHECK_EQUAL(a + b, 3);
}