C++ 独立功能
C++ freestanding features
我可以在 C++ 独立环境中使用哪些功能？我正在开发一个小内核（为了我自己的乐趣），我知道我不能使用整个 stdlib 库，但还有什么？当我尝试使用 new 和 delete 运算符时，它编译时没有遇到任何问题，但是 linker 说
undefined reference to `operator new[](unsigned long)
undefined reference to `operator delete[](void*)'
我 link 有 -lgcc 和 -lsupc++ 选项。我知道异常处理在独立模式下是禁用的，但我有点惊讶 new 和 delete 也是。那我能用什么不能用呢？
What are the features that I can use in c++ freestanding environment?
许多独立的实现是实现定义的：
[intro.compliance] ... A freestanding
implementation is one in which execution may take place without the benefit of an operating system, and
has an implementation-defined set of libraries that includes certain language-support libraries
[intro.multithread] ... Under a freestanding implementation, it is implementation-defined whether
a program can have more than one thread of execution.
[basic.start.main] It
is implementation-defined whether a program in a freestanding environment is required to define a main
function. [ Note: In a freestanding environment, start-up and termination is implementation-defined; start-
up contains the execution of constructors for objects of namespace scope with static storage duration;
termination contains the execution of destructors for objects with static storage duration. — end note ]
[using.headers] C ++ headers for freestanding implementations
<ciso646>
<cstddef>
<cfloat>
<limits>
<climits>
<cstdint>
<cstdlib>
<new>
<typeinfo>
<exception>
<initializer_list>
<cstdalign>
<cstdarg>
<cstdbool>
<atomic>
[compliance] The supplied version of the header <cstdlib> shall declare at least the functions abort, atexit, at_quick_-
exit, exit, and quick_exit (18.5). The other headers listed in this table shall meet the same requirements
as for a hosted implementation.
请注意，malloc/free未列在<cstdlib>所需的函数中。
就您的链接器错误而言，既不需要独立实现也不需要托管实现来提供这些重载：
[replacement.functions] A C ++ program may provide the definition for any of twelve dynamic memory allocation function signatures
declared in header <new>
实际上，由于独立环境不能依赖 OS，并且 malloc 通常使用 OS 提供的功能来实现，因此不太可能有免费存储独立环境中的内存管理功能。相反，托管环境需要自由存储内存管理来实现标准库的功能。
我可以在 C++ 独立环境中使用哪些功能？我正在开发一个小内核（为了我自己的乐趣），我知道我不能使用整个 stdlib 库，但还有什么？当我尝试使用 new 和 delete 运算符时，它编译时没有遇到任何问题，但是 linker 说
undefined reference to `operator new[](unsigned long)
undefined reference to `operator delete[](void*)'
我 link 有 -lgcc 和 -lsupc++ 选项。我知道异常处理在独立模式下是禁用的，但我有点惊讶 new 和 delete 也是。那我能用什么不能用呢？
What are the features that I can use in c++ freestanding environment?
许多独立的实现是实现定义的：
[intro.compliance] ... A freestanding implementation is one in which execution may take place without the benefit of an operating system, and has an implementation-defined set of libraries that includes certain language-support libraries
[intro.multithread] ... Under a freestanding implementation, it is implementation-defined whether a program can have more than one thread of execution.
[basic.start.main] It is implementation-defined whether a program in a freestanding environment is required to define a main function. [ Note: In a freestanding environment, start-up and termination is implementation-defined; start- up contains the execution of constructors for objects of namespace scope with static storage duration; termination contains the execution of destructors for objects with static storage duration. — end note ]
[using.headers] C ++ headers for freestanding implementations
<ciso646> <cstddef> <cfloat> <limits> <climits> <cstdint> <cstdlib> <new> <typeinfo> <exception> <initializer_list> <cstdalign> <cstdarg> <cstdbool> <atomic>[compliance] The supplied version of the header
<cstdlib>shall declare at least the functions abort, atexit, at_quick_- exit, exit, and quick_exit (18.5). The other headers listed in this table shall meet the same requirements as for a hosted implementation.
请注意，malloc/free未列在<cstdlib>所需的函数中。
就您的链接器错误而言，既不需要独立实现也不需要托管实现来提供这些重载：
[replacement.functions] A C ++ program may provide the definition for any of twelve dynamic memory allocation function signatures declared in header
<new>
实际上，由于独立环境不能依赖 OS，并且 malloc 通常使用 OS 提供的功能来实现，因此不太可能有免费存储独立环境中的内存管理功能。相反，托管环境需要自由存储内存管理来实现标准库的功能。