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[diff.cpp17.lex]

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  1. tmp/tmp8hsxib4x/{from.md → to.md} +20 -5
tmp/tmp8hsxib4x/{from.md → to.md} RENAMED
@@ -1,11 +1,13 @@
1
  ### [[lex]]: lexical conventions <a id="diff.cpp17.lex">[[diff.cpp17.lex]]</a>
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  **Change:** New identifiers with special meaning. **Rationale:**
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  Required for new features. **Effect on original feature:** Logical lines
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  beginning with `module` or `import` may be interpreted differently in
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- this revision of C++. For example:
 
 
7
 
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  ``` cpp
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  class module {};
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  module m1; // was variable declaration; now module-declaration
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  module *m2; // variable declaration
@@ -13,21 +15,27 @@ module *m2; // variable declaration
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  class import {};
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  import j1; // was variable declaration; now module-import-declaration
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  ::import j2; // variable declaration
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  ```
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  **Change:** *header-name* tokens are formed in more contexts.
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  **Rationale:** Required for new features. **Effect on original
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  feature:** When the identifier `import` is followed by a `<` character,
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- a *header-name* token may be formed. For example:
 
 
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  ``` cpp
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  template<typename> class import {};
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  import<int> f(); // ill-formed; previously well-formed
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  ::import<int> g(); // OK
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  ```
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  **Change:** New keywords. **Rationale:** Required for new features.
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  - The `char8_t` keyword is added to differentiate the types of ordinary
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  and UTF-8 literals [[lex.string]].
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  - The `concept` keyword is added to enable the definition of concepts
@@ -47,29 +55,34 @@ Valid C++17 code using `char8_t`, `concept`, `consteval`, `constinit`,
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  not valid in this revision of C++.
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  **Change:** New operator `<=>`. **Rationale:** Necessary for new
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  functionality. **Effect on original feature:** Valid C++17 code that
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  contains a `<=` token immediately followed by a `>` token may be
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- ill-formed or have different semantics in this revision of C++. For
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- example:
 
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  ``` cpp
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  namespace N {
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  struct X {};
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  bool operator<=(X, X);
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  template<bool(X, X)> struct Y {};
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  Y<operator<=> y; // ill-formed; previously well-formed
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  }
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  ```
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  **Change:** Type of UTF-8 string and character literals. **Rationale:**
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  Required for new features. The changed types enable function
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  overloading, template specialization, and type deduction to distinguish
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  ordinary and UTF-8 string and character literals. **Effect on original
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  feature:** Valid C++17 code that depends on UTF-8 string literals having
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  type “array of `const char`” and UTF-8 character literals having type
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- “`char`” is not valid in this revision of C++. For example:
 
 
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  ``` cpp
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  const auto *u8s = u8"text"; // u8s previously deduced as const char*; now deduced as const char8_t*
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  const char *ps = u8s; // ill-formed; previously well-formed
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@@ -86,5 +99,7 @@ template<> struct ct<char> {
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  using type = char;
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  };
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  ct<decltype(u8'c')>::type x; // ill-formed; previously well-formed.
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  ```
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1
  ### [[lex]]: lexical conventions <a id="diff.cpp17.lex">[[diff.cpp17.lex]]</a>
2
 
3
  **Change:** New identifiers with special meaning. **Rationale:**
4
  Required for new features. **Effect on original feature:** Logical lines
5
  beginning with `module` or `import` may be interpreted differently in
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+ this revision of C++.
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+
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+ [*Example 1*:
9
 
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  ``` cpp
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  class module {};
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  module m1; // was variable declaration; now module-declaration
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  module *m2; // variable declaration
 
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  class import {};
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  import j1; // was variable declaration; now module-import-declaration
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  ::import j2; // variable declaration
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  ```
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+ — *end example*]
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+
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  **Change:** *header-name* tokens are formed in more contexts.
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  **Rationale:** Required for new features. **Effect on original
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  feature:** When the identifier `import` is followed by a `<` character,
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+ a *header-name* token may be formed.
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+
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+ [*Example 2*:
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  ``` cpp
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  template<typename> class import {};
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  import<int> f(); // ill-formed; previously well-formed
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  ::import<int> g(); // OK
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  ```
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+ — *end example*]
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+
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  **Change:** New keywords. **Rationale:** Required for new features.
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  - The `char8_t` keyword is added to differentiate the types of ordinary
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  and UTF-8 literals [[lex.string]].
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  - The `concept` keyword is added to enable the definition of concepts
 
55
  not valid in this revision of C++.
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  **Change:** New operator `<=>`. **Rationale:** Necessary for new
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  functionality. **Effect on original feature:** Valid C++17 code that
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  contains a `<=` token immediately followed by a `>` token may be
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+ ill-formed or have different semantics in this revision of C++.
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+
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+ [*Example 3*:
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  ``` cpp
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  namespace N {
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  struct X {};
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  bool operator<=(X, X);
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  template<bool(X, X)> struct Y {};
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  Y<operator<=> y; // ill-formed; previously well-formed
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  }
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  ```
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+ — *end example*]
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+
75
  **Change:** Type of UTF-8 string and character literals. **Rationale:**
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  Required for new features. The changed types enable function
77
  overloading, template specialization, and type deduction to distinguish
78
  ordinary and UTF-8 string and character literals. **Effect on original
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  feature:** Valid C++17 code that depends on UTF-8 string literals having
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  type “array of `const char`” and UTF-8 character literals having type
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+ “`char`” is not valid in this revision of C++.
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+
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+ [*Example 4*:
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  ``` cpp
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  const auto *u8s = u8"text"; // u8s previously deduced as const char*; now deduced as const char8_t*
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  const char *ps = u8s; // ill-formed; previously well-formed
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  using type = char;
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  };
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  ct<decltype(u8'c')>::type x; // ill-formed; previously well-formed.
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  ```
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+ — *end example*]
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+