добавил новый проект для модульных тестов

histogram.cpp

@@ -4,7 +4,7 @@
 #include "histogram.h"
 using namespace std;
 
-void static find_minmax(const vector<double> &numbers, double &min, double &max)
+void find_minmax(const vector<double> &numbers, double &min, double &max)
 {
     max = numbers[0];
     min = numbers[1];

histogram_internal.h

@@ -0,0 +1,8 @@
+#ifndef HISTOGRAM_INTERNAL_H_INCLUDED
+#define HISTOGRAM_INTERNAL_H_INCLUDED
+#include <vector>
+
+void find_minmax(const std::vector<double> &numbers, double &min, double &max);
+
+
+#endif // HISTOGRAM_INTERNAL_H_INCLUDED

unittest.cpp

@@ -0,0 +1,12 @@
+#define DOCTEST_CONFIG_NO_MULTITHREADING
+#define DOCTEST_CONFIG_IMPLEMENT_WITH_MAIN
+#include "doctest.h"
+#include "histogram_internal.h"
+
+TEST_CASE("distinct positive numbers") {
+    double min = 0;
+    double max = 0;
+    find_minmax({1, 2}, min, max);
+    CHECK(min == 1);
+    CHECK(max == 2);
+}