depish/cppdraft_translate
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Init

Browse Source
This commit is contained in:
Leonov Artur (Depish)
2025-10-25 03:02:53 +03:00
commit 043225d523
3416 changed files with 681196 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

298
cppdraft/support/rtti.md Normal file
View File

@@ -0,0 +1,298 @@
[support.rtti]
# 17 Language support library [[support]](./#support)
## 17.7 Type identification [support.rtti]
### [17.7.1](#general) General [[support.rtti.general]](support.rtti.general)
[1](#general-1)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3264)
The header [<typeinfo>](#header:%3ctypeinfo%3e "17.7.2 Header <typeinfo> synopsis [typeinfo.syn]") defines a
type associated with type information generated by the implementation[.](#general-1.sentence-1)
It also defines two types for reporting dynamic type identification errors[.](#general-1.sentence-2)
The header [<typeindex>](#header:%3ctypeindex%3e "17.7.6 Header <typeindex> synopsis [type.index.synopsis]") defines
a wrapper type for use as an index type in associative containers ([[associative]](associative "23.4 Associative containers"))
and in unordered associative containers ([[unord]](unord "23.5 Unordered associative containers"))[.](#general-1.sentence-3)
### [17.7.2](#typeinfo.syn) Header <typeinfo> synopsis [[typeinfo.syn]](typeinfo.syn)
[🔗](#header:%3ctypeinfo%3e)
// all freestandingnamespace std {class type_info; class bad_cast; class bad_typeid;}
### [17.7.3](#type.info) Class type_info [[type.info]](type.info)
[🔗](#lib:type_info_)
namespace std {class type_info {public:virtual ~type_info(); constexpr bool operator==(const type_info& rhs) const noexcept; bool before(const type_info& rhs) const noexcept;
size_t hash_code() const noexcept; const char* name() const noexcept;
type_info(const type_info&) = delete;
type_info& operator=(const type_info&) = delete; };}
[1](#type.info-1)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3306)
The classtype_info describes type information generated by the implementation ([[expr.typeid]](expr.typeid "7.6.1.8 Type identification"))[.](#type.info-1.sentence-1)
Objects of this class effectively store a pointer to a name for the type, and
an encoded value suitable for comparing two types for equality or collating order[.](#type.info-1.sentence-2)
The names, encoding rule, and collating sequence for types are all unspecifiedand may differ between programs[.](#type.info-1.sentence-3)
[🔗](#lib:operator==,type_info)
`constexpr bool operator==(const type_info& rhs) const noexcept;
`
[2](#type.info-2)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3322)
*Effects*: Compares the current object with rhs[.](#type.info-2.sentence-1)
[3](#type.info-3)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3326)
*Returns*: true if the two values describe the same type[.](#type.info-3.sentence-1)
[🔗](#lib:before,type_info)
`bool before(const type_info& rhs) const noexcept;
`
[4](#type.info-4)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3338)
*Effects*: Compares the current object with rhs[.](#type.info-4.sentence-1)
[5](#type.info-5)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3342)
*Returns*: true if*this precedes rhs in the implementation's collation order[.](#type.info-5.sentence-1)
[🔗](#lib:hash_code,type_info)
`size_t hash_code() const noexcept;
`
[6](#type.info-6)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3356)
*Returns*: An unspecified value, except that within a single execution of the
program, it shall return the same value for any two type_info objects which compare equal[.](#type.info-6.sentence-1)
[7](#type.info-7)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3362)
*Remarks*: An implementation should return different values for twotype_info objects which do not compare equal[.](#type.info-7.sentence-1)
[🔗](#lib:name,type_info)
`const char* name() const noexcept;
`
[8](#type.info-8)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3375)
*Returns*: An implementation-defined ntbs[.](#type.info-8.sentence-1)
[9](#type.info-9)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3379)
*Remarks*: The message may be a[null-terminated multibyte string](multibyte.strings#def:ntmbs "16.3.3.3.4.3 Multibyte strings [multibyte.strings]"),
suitable for conversion and display as awstring ([[string.classes]](string.classes "27.4 String classes"), [[locale.codecvt]](locale.codecvt "28.3.4.2.5 Class template codecvt"))[.](#type.info-9.sentence-1)
### [17.7.4](#bad.cast) Class bad_cast [[bad.cast]](bad.cast)
[🔗](#lib:bad_cast_)
namespace std {class bad_cast : public exception {public:// see [[exception]](exception "17.9.3 Class exception") for the specification of the special member functionsconstexpr const char* what() const noexcept override; };}
[1](#bad.cast-1)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3401)
The classbad_cast defines the type of objects thrown
as exceptions by the implementation to report the execution of an invaliddynamic_cast expression ([[expr.dynamic.cast]](expr.dynamic.cast "7.6.1.7 Dynamic cast"))[.](#bad.cast-1.sentence-1)
[🔗](#lib:what,bad_cast)
`constexpr const char* what() const noexcept override;
`
[2](#bad.cast-2)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3416)
*Returns*: An implementation-defined ntbs[.](#bad.cast-2.sentence-1)
### [17.7.5](#bad.typeid) Class bad_typeid [[bad.typeid]](bad.typeid)
[🔗](#lib:bad_typeid_)
namespace std {class bad_typeid : public exception {public:// see [[exception]](exception "17.9.3 Class exception") for the specification of the special member functionsconstexpr const char* what() const noexcept override; };}
[1](#bad.typeid-1)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3435)
The classbad_typeid defines the type of objects
thrown as exceptions by the implementation to report a null pointer
in atypeid expression ([[expr.typeid]](expr.typeid "7.6.1.8 Type identification"))[.](#bad.typeid-1.sentence-1)
[🔗](#lib:what,bad_typeid)
`constexpr const char* what() const noexcept override;
`
[2](#bad.typeid-2)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3450)
*Returns*: An implementation-defined ntbs[.](#bad.typeid-2.sentence-1)
### [17.7.6](#type.index.synopsis) Header <typeindex> synopsis [[type.index.synopsis]](type.index.synopsis)
[🔗](#header:%3ctypeindex%3e)
#include <compare> // see [[compare.syn]](compare.syn "17.12.1 Header <compare> synopsis")namespace std {class type_index; template<class T> struct hash; template<> struct hash<type_index>;}
### [17.7.7](#type.index) Class type_index [[type.index]](type.index)
[🔗](#lib:type_index)
namespace std {class type_index {public: type_index(const type_info& rhs) noexcept; bool operator==(const type_index& rhs) const noexcept; bool operator< (const type_index& rhs) const noexcept; bool operator> (const type_index& rhs) const noexcept; bool operator<=(const type_index& rhs) const noexcept; bool operator>=(const type_index& rhs) const noexcept;
strong_ordering operator<=>(const type_index& rhs) const noexcept;
size_t hash_code() const noexcept; const char* name() const noexcept; private:const type_info* target; // *exposition only*// Note that the use of a pointer here, rather than a reference,// means that the default copy/move constructor and assignment// operators will be provided and work as expected.};}
[1](#type.index-1)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3494)
The class type_index provides a simple wrapper fortype_info which can be used as an index type in associative
containers ([[associative]](associative "23.4 Associative containers")) and in unordered associative
containers ([[unord]](unord "23.5 Unordered associative containers"))[.](#type.index-1.sentence-1)
[🔗](#lib:type_index,constructor)
`type_index(const type_info& rhs) noexcept;
`
[2](#type.index-2)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3506)
*Effects*: Constructs a type_index object, the equivalent of target = &rhs[.](#type.index-2.sentence-1)
[🔗](#lib:operator==,type_index)
`bool operator==(const type_index& rhs) const noexcept;
`
[3](#type.index-3)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3517)
*Returns*: *target == *rhs.target[.](#type.index-3.sentence-1)
[🔗](#lib:operator%3c,type_index)
`bool operator<(const type_index& rhs) const noexcept;
`
[4](#type.index-4)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3528)
*Returns*: target->before(*rhs.target)[.](#type.index-4.sentence-1)
[🔗](#lib:operator%3e,type_index)
`bool operator>(const type_index& rhs) const noexcept;
`
[5](#type.index-5)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3539)
*Returns*: rhs.target->before(*target)[.](#type.index-5.sentence-1)
[🔗](#lib:operator%3c=,type_index)
`bool operator<=(const type_index& rhs) const noexcept;
`
[6](#type.index-6)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3550)
*Returns*: !rhs.target->before(*target)[.](#type.index-6.sentence-1)
[🔗](#lib:operator%3e=,type_index)
`bool operator>=(const type_index& rhs) const noexcept;
`
[7](#type.index-7)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3561)
*Returns*: !target->before(*rhs.target)[.](#type.index-7.sentence-1)
[🔗](#lib:operator%3c=%3e,type_index)
`strong_ordering operator<=>(const type_index& rhs) const noexcept;
`
[8](#type.index-8)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3572)
*Effects*: Equivalent to:if (*target == *rhs.target) return strong_ordering::equal;if (target->before(*rhs.target)) return strong_ordering::less;return strong_ordering::greater;
[🔗](#lib:hash_code,type_index)
`size_t hash_code() const noexcept;
`
[9](#type.index-9)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3588)
*Returns*: target->hash_code()[.](#type.index-9.sentence-1)
[🔗](#lib:name,type_index)
`const char* name() const noexcept;
`
[10](#type.index-10)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3599)
*Returns*: target->name()[.](#type.index-10.sentence-1)
[🔗](#lib:hash,type_index)
`template<> struct hash<type_index>;
`
[11](#type.index-11)
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L3610)
For an object index of type type_index,hash<type_index>()(index) shall evaluate to the same result as index.hash_code()[.](#type.index-11.sentence-1)