[C++知识库]C++学习1——英文环境学习

找到资源网站 C++ reference（网址：en.cppreference.com)

Language

? ? ? ? Basic concepts

? ? ? ? declaration, translation, main function, keywords, identifiers, comments, escape sequences

? ? ? ? objects, references, structured bindings, functions, enumerators, types, templates, template specializations, namespaces, parameter packs, statements, expressions, name lookup, non-static data members.

? ? ? ? Keywords

? ? ? ? these keywords are not available for re-definition or overloading.

? ? ? ? alignas, alignof, and, and_eq, asm, atomic_cancel, atomic_commit, atomic_noexcept, auto, ????????bitand, bitor, bool, break, case, catch, char, char8_t, char16_t, char32_t, class, compl, ????????concept, const, consteval, constexpr, constinit, const_cast, cotinue, co_await, co_return, ????????co_yield, decltype, default, delete, do, double, dynamic_cast, else, num, explicit, export, ????????extern, false, float, for, friend, goto, if, inline, int, long, mutable, namespace, new, noexcept, ????????not, not_eq, nullptr, operator, or, or_eq, private, protected, public, reflexpr, register, ????????reinterpret_cast, requires, return, short, signed, sizeof, static, static_assert, static_cast, ????????struct, switch, synchronized, template, this, thread_local, throw, true,try, typedef, typeid, ????????typename, union, unsigned, using, virtual, void, volatile, wchar_t, while, xor, xor_eq

? ? ? ? Preprocessor

? ? ? ? The result of preprocessing is a single file which is then passed to the actual compiler.

? ? ? ? format as follos:

? ? ? ? # character?

? ? ? ? preprocessing instruction ( one of define, undef, include, if, ifdef, else, elif, endif, line, error, pragma)

? ? ? ? line break?

#define EMPTY
EMPTY   # include<file.h> //not a preprocessing directive

????????Capbilities

? ? ? ? conditionally? compile of parts of source file (controlled by directive #if, #ifdef, #ifndef, #else, #elif and #endif)

? ? ? ? replace text macros while possibly concatenating or quoting identifiers ( controlled by directives #define and #undef, and operators # and ##)

? ? ? ? include other files (controlled by directive? #include and checked with? has_include

? ? ? ? cause an error (controlled by #error)

? ? ? ? The following aspects of the preprocessor? can be controlled:

? ? ? ? ? ? ? ? implementation defined behavior (controlled by directive #pragma and operator _Pragma. In addition, some compilers support t(to varying degrees) the operator _Pragma as a non-standard extension.

? ? ? ? ? ? ? ? file name and line information avaliable to the preprocessor (controlled by directive #line)

? ? ? ? Expressions?

? ? ? ? An expression is a sequence of opereators and their operands, that specifies a computation. Each C++ expression is characterized by two independent properties: A type and a value category.

? ? ? ? value categories; order of evaluation?

? ? ? ? Operators; Conversions; Memory allocation; Other

? ? ? ? Primary expressions (Literals, Id-expressions, Lambada-expressions, Fold-expressions, Requires-expressions); Literals ( integer literals, character literals, floating-point literals, string literals, boolean literals, nullptr, user-defined literals); Unevaluated expressions;Discard expressions.

? ? ? ? Declarations

? ? ? ? ? ? ? ?Declarations introduce names into the C++ program. A declaration is one of the following:

? ? ? ? ? ? ? ? Function definition; Template declaration; Explicit template instantiation; Explicit template specialization; Namespace definition; Linkage specification; Attribute declaration; Empty declaration; A function declaration without a decl-specifier-seq; block declaration

????????Initialization

? ? ? ? Initization of a variable provides its initial value at the time of construction.

? ? ? ? Non-local variables; ( static initialization, Dynamic initialization)

经过一番学习，感想是优点在于懂得了并深刻理解了很多词汇深层次的意思，但是缺点就是感觉没有学到除了单词之外的其他东西。当然缺点也有可能是因为目前还没有学到很多与以前不同的知识所致。

? ? ? ??

?