在这种情况下，老式的C程序员使用goto。这是goto的一种用法，实际上是Linux样式指南鼓励的，它被称为集中函数exit:

int foo() {
    int result = /*some error code*/;
    if(!executeStepA()) goto cleanup;
    if(!executeStepB()) goto cleanup;
    if(!executeStepC()) goto cleanup;

    result = 0;
cleanup:
    executeThisFunctionInAnyCase();
    return result;
}

有些人使用goto的方法是将body包装成一个循环并将其断开，但实际上这两种方法做的是同一件事。如果你只在executeStepA()成功时才需要一些其他的清理，那么goto方法会更好:

int foo() {
    int result = /*some error code*/;
    if(!executeStepA()) goto cleanupPart;
    if(!executeStepB()) goto cleanup;
    if(!executeStepC()) goto cleanup;

    result = 0;
cleanup:
    innerCleanup();
cleanupPart:
    executeThisFunctionInAnyCase();
    return result;
}

使用循环方法，在这种情况下，您将得到两级循环。

如果条件被移动到单独的步骤下，条件可以被简化，这是一个c#伪代码，

其思想是使用编排而不是中央编排。

void Main()
{
    Request request = new Request();
    Response response = null;

    // enlist all the processors
    var processors = new List<IProcessor>() {new StepA() };

    var factory = new ProcessorFactory(processors);

    // execute as a choreography rather as a central orchestration.
    var processor = factory.Get(request, response);
    while (processor != null)
    {
        processor.Handle(request, out response);
        processor = factory.Get(request, response); 
    }

    // final result...
    //response
}

public class Request
{
}

public class Response
{
}

public interface IProcessor
{
    bool CanProcess(Request request, Response response);
    bool Handle(Request request, out Response response);
}

public interface IProcessorFactory
{
    IProcessor Get(Request request, Response response);
}   

public class ProcessorFactory : IProcessorFactory
{
    private readonly IEnumerable<IProcessor> processors;

    public ProcessorFactory(IEnumerable<IProcessor> processors)
    {
        this.processors = processors;
    }

    public IProcessor Get(Request request, Response response)
    {
        // this is an iterator
        var matchingProcessors = processors.Where(x => x.CanProcess(request, response)).ToArray();

        if (!matchingProcessors.Any())
        {
            return null;
        }

        return matchingProcessors[0];
    }
}

// Individual request processors, you will have many of these...
public class StepA: IProcessor
{
    public bool CanProcess(Request request, Response response)
    {
        // Validate wether this can be processed -- if condition here
        return false;
    }

    public bool Handle(Request request, out Response response)
    {
        response = null;
        return false;
    }
}

以下是我在C-whatever和Java中使用过的一个技巧:

do {
    if (!condition1) break;
    doSomething();
    if (!condition2) break;
    doSomethingElse()
    if (!condition3) break;
    doSomethingAgain();
    if (!condition4) break;
    doYetAnotherThing();
} while(FALSE);  // Or until(TRUE) or whatever your language likes

我更喜欢它而不是嵌套的if，因为它的清晰度，特别是当每个条件都有明确的注释时。

你也可以这样做:

bool isOk = true;
std::vector<bool (*)(void)> funcs; //vector of function ptr

funcs.push_back(&executeStepA);
funcs.push_back(&executeStepB);
funcs.push_back(&executeStepC);
//...

//this will stop at the first false return
for (auto it = funcs.begin(); it != funcs.end() && isOk; ++it) 
    isOk = (*it)();
if (isOk)
 //doSomeStuff
executeThisFunctionInAnyCase();

通过这种方式，您可以获得最小的线性增长大小，每次调用+1行，并且易于维护。

编辑:(谢谢@Unda)我不太喜欢，因为在我看来你失去了能见度:

bool isOk = true;
auto funcs { //using c++11 initializer_list
    &executeStepA,
    &executeStepB,
    &executeStepC
};

for (auto it = funcs.begin(); it != funcs.end() && isOk; ++it) 
    isOk = (*it)();
if (isOk)
 //doSomeStuff
executeThisFunctionInAnyCase();

假设你不需要单独的条件变量，反转测试并使用else-falthrough作为“ok”路径，将允许你获得更垂直的if/else语句集:

bool failed = false;

// keep going if we don't fail
if (failed = !executeStepA())      {}
else if (failed = !executeStepB()) {}
else if (failed = !executeStepC()) {}
else if (failed = !executeStepD()) {}

runThisFunctionInAnyCase();

省略失败的变量使代码在我看来有点太晦涩了。

在里面声明变量就可以了，不用担心= vs ==。

// keep going if we don't fail
if (bool failA = !executeStepA())      {}
else if (bool failB = !executeStepB()) {}
else if (bool failC = !executeStepC()) {}
else if (bool failD = !executeStepD()) {}
else {
     // success !
}

runThisFunctionInAnyCase();

这很模糊，但很紧凑:

// keep going if we don't fail
if (!executeStepA())      {}
else if (!executeStepB()) {}
else if (!executeStepC()) {}
else if (!executeStepD()) {}
else { /* success */ }

runThisFunctionInAnyCase();

在c++中，实际上有一种方法可以延迟操作:使用对象的析构函数。

假设你可以访问c++ 11:

class Defer {
public:
    Defer(std::function<void()> f): f_(std::move(f)) {}
    ~Defer() { if (f_) { f_(); } }

    void cancel() { f_ = std::function<void()>(); }

private:
    Defer(Defer const&) = delete;
    Defer& operator=(Defer const&) = delete;

    std::function<void()> f_;
}; // class Defer

然后使用这个工具:

int foo() {
    Defer const defer{&executeThisFunctionInAnyCase}; // or a lambda

    // ...

    if (!executeA()) { return 1; }

    // ...

    if (!executeB()) { return 2; }

    // ...

    if (!executeC()) { return 3; }

    // ...

    return 4;
} // foo