main()函数是否已使用? [英] Is the main() function odr-used?

问题描述

是main()函数是使用过 ?例如，在这样的简单程序中:

Is the main() function odr-used? E.g in the simple program like this:

int main()
{
}

推荐答案

不，不是.不在您的简单程序中.

No, it is not. Not in your simple program.

[basic.def.odr]

3 一个函数的名称显示为潜在评估 如果表达式是唯一的查找结果或 一组重载函数([basic.lookup]， [over.match]，[over.over])，除非它是纯虚函数并且 其名称未明确限定，或者该表达式形成一个 指向成员([expr.unary.op])的指针.

3 A function whose name appears as a potentially-evaluated expression is odr-used if it is the unique lookup result or the selected member of a set of overloaded functions ([basic.lookup], [over.match], [over.over]), unless it is a pure virtual function and either its name is not explicitly qualified or the expression forms a pointer to member ([expr.unary.op]).

main不会出现在可能评估的表达式中，因此不会被过度使用.此外，我们必须考虑以下几点:

main does not appear in a potentially evaluated expression, as such it is not odr-used. Furthermore, we must consider the following:

[basic.start.main]

3 不得使用main函数在程序中.

3 The function main shall not be used within a program.

这是否适用于简单的调用 main或任何用途，还是有争议的，但这无疑将您的选择限制为在任何程序中使用odr-use main.

Whether or not that applies to simply calling main, or any use, is maybe debatable, but it certainly limits your options to odr-use main in any program.

在分析odr-use时值得牢记的是，odr-uses实体(或不使用它们)是程序.外部力量(例如使用main作为切入点的实施方式)无需争论.

It's worth keeping in mind when analyzing odr-use that it is the program that odr-uses entities (or not uses them). Outside forces (such as the implementation using main as the entry point) are not subject to that debate.

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