C ++，我可以在编译时静态初始化std :: map吗？ [英] C++, can I statically initialize a std::map at compile time?

问题描述

如果我编码此

std::map<int, char> example = {
                                (1, 'a'),
                                (2, 'b'),
                                (3, 'c') 
                              };

然后g ++对我说

deducing from brace-enclosed initializer list requires #include <initializer_list>
in C++98 ‘example’ must be initialized by constructor, not by ‘{...}’   

并且使我略微恼火，因为构造函数是运行时，并且理论上可能会失败。

and that annoys me slightly because the constructor is run-time and can, theoretically fail.

当然，如果是这样，它会很快失败，应该这样一直，所以我应该快速找到&修正问题。

Sure, if it does, it will fail quickly and ought to do so consistently, so that I ought to quickly locate & correct the problem.

但是，我很好奇 - 在编译时是否还要初始化map，vector等等？

But, still, I am curious - is there anyway to initialize map, vector, etc, at compile time?

编辑：我应该说我正在为嵌入式系统开发。并非所有处理器都有C ++ 0x编译器。最流行的可能会，但我不想遇到一个骗子&必须维护2个版本的代码。

I should have said that I am developing for embedded systems. Not all processors will have a C++0x compiler. The most popular probably will, but I don't want to encounter a gotcha & have to maintain 2 versions of the code.

至于Boost，我未定。他们对在有限状态机类在嵌入式系统中使用的希望是清洗，所以这实际上是我在这里编码，事件/状态/ Fsm类。

As to Boost, I am undecided. They are wishy-washy on the use of their Finite State Machine classes in embedded systems, so that is actually what I am coding here, Event/State/Fsm classes.

叹息，我想我最好只是安全地玩，但我希望这个讨论对其他人有帮助。

Sigh, I guess I'd better just play it safe, but I hope that this discussion has been helpful for others.

推荐答案

不在C ++ 98。 C ++ 11支持这一点，所以如果你启用C ++ 11标志并包含g ++的建议，你可以。

Not in C++98. C++11 supports this, so if you enable C++11 flags and include what g++ suggests, you can.

编辑：从gcc 5 C ++ 11默认情况下启用

from gcc 5 C++11 is on by default

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