下面的代码使用#define宏。我想避免这种情况,但是我看不到使用C++功能并且可读性更好的方法。该代码用于测试将ClassUnderTest的两个实例合并为一个的PoorLegacyClass类。此PoorLegacyClass具有许多getter和setter,并且出于测试目的,我需要调用很多setter(或者,是吗?)。

简而言之,不是写作

a.setValueX(20);
b.setValueX(30);

我想写点东西
set(a, b, ValueX, 20, 30);
// or
set<ValueX>(a, 20, b, 30);
// or even
set(a, b, &PoorLegacyClass::setValueX, 20, 30);

这是类似于我目前使用的代码的代码:
#include <boost/test/unit_test.hpp>

#include "ClassUnderTest.h"

BOOST_AUTO_TEST_SUITE(Test_ClassUnderTest);

#define SETTER_A_B(fieldname, valueA, valueB)\
        a.set##fieldname(valueA);\
        b.set##fieldname(valueB);

struct TestContext
{
    PoorLegacyClass a, b;
};

BOOST_FIXTURE_TEST_CASE(ClassUnderTest_meaningful_description1, TestContext)
{
    SETTER_A_B(ValueX, 20, 30);
    auto result = ClassUnderTest().merge(a, b);

    BOOST_TEST(20 == result.getValueX());
}

BOOST_FIXTURE_TEST_CASE(ClassUnderTest_meaningful_description2, TestContext)
{
    SETTER_A_B(ValueY, 21, 37);
    auto result = ClassUnderTest().merge(a, b);

    BOOST_TEST(21 + 37 == result.getValueY());
}

BOOST_FIXTURE_TEST_CASE(ClassUnderTest_meaningful_description3, TestContext)
{
    SETTER_A_B(ValueZ, 12, 83);
    auto result = ClassUnderTest().merge(a, b);

    BOOST_TEST(12 + 83 == result.getValueZ());
}

BOOST_FIXTURE_TEST_CASE(ClassUnderTest_meaningful_description4, TestContext)
{
    SETTER_A_B(ValueY, 212, 37);
    SETTER_A_B(ValueX, 20, 30);
    auto result = ClassUnderTest().merge(a, b);

    BOOST_TEST(a.getValueY() == result.getValueY());
}

// more test cases that are similar to those above

BOOST_AUTO_TEST_SUITE_END();

虽然我将来会重构PoorLegacyClass,但这不是这个问题的主题。不过,我想知道的是如何避免使用#define宏。

最佳答案

由于您愿意接受语法set(a, b, &PoorLegacyClass::setValueX, 20, 30);,因此实现这样的set应该很容易:

template <class T>
void set(PoorLegacyClass &a, PoorLegacyClass &b, void (PoorLegacyClass::*setter)(T), T valForA, T valForB)
{
  (a.*setter)(valForA);
  (b.*setter)(valForB);
}

您也可以这样做,以便valFor参数在非推导上下文中使用T,以便只能从setter推导T,并对值进行隐式转换:
template <class T>
struct NonDeduced { using type = T; }

template <class T>
void set(PoorLegacyClass &a, PoorLegacyClass &b, void (PoorLegacyClass::*setter)(T), typename NonDeduced<T>::type valForA, typename NonDeduced<T>::type valForB)

09-06 17:48