Ruby
3.4.0dev (2024-12-06 revision 892c46283a5ea4179500d951c9d4866c0051f27b)
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Defines RBIMPL_ATTR_NOEXCEPT. More...
Go to the source code of this file.
Macros | |
#define | RBIMPL_ATTR_NOEXCEPT(_) noexcept(noexcept(_)) |
Wraps (or simulates) C++11 noexcept More... | |
Defines RBIMPL_ATTR_NOEXCEPT.
RBIMPL
or rbimpl
are implementation details. Don't take them as canon. They could rapidly appear then vanish. The name (path) of this header file is also an implementation detail. Do not expect it to persist at the place it is now. Developers are free to move it anywhere anytime at will. __VA_ARGS__
is always available. We assume C99 for ruby itself but we don't assume languages of extension libraries. They could be written in C++98.This isn't actually an attribute in C++ but who cares...
Mainly due to aesthetic reasons, this one is rarely used in the project. But can be handy on occasions, especially when a function's noexcept-ness depends on its calling functions.
noexcept
?noexcept
is about C++ exceptions, not Ruby's. They don't interface each other. You can safely attribute a function that raises Ruby exceptions as noexcept
.__attribute__((__leaf__))
is for that purpose. A function attributed as leaf can still throw C++ exceptions, but not Ruby's. Note however, that it's extremely difficult – if not impossible – to assert that a function doesn't raise any Ruby exceptions at all. Use of that attribute is not recommended; mere mortals can't properly use that by hand.noexcept
?noexcept
actually doesn't throw any exceptions at all: these days I don't see any difference in generated assembly by adding/removing this attribute. C++ compilers get smarter and smarter. Today they can infer if it actually throws or not without any annotations by humans (correct me if I'm wrong).noexcept
actually does throw an exception: they have to call std::terminate
then (C++ standard mandates so). This means exception handling routines are actually enforced, not omitted. This doesn't impact runtime performance (The Itanium C++ ABI has zero-cost exception handling), but does impact on generated binary size. This is bad. Definition in file noexcept.h.
Wraps (or simulates) C++11 noexcept
Definition at line 73 of file noexcept.h.