diff --git a/cppguide.html b/cppguide.html index a7f32245a..8404516b3 100644 --- a/cppguide.html +++ b/cppguide.html @@ -174,9 +174,8 @@

C++ Version

Do not use non-standard extensions.

-
Consider portability to other environments -before using features from C++14 and C++17 in your project. -
+

Consider portability to other environments +before using features from C++14 and C++17 in your project.

Header Files

@@ -230,15 +229,11 @@

The #define Guard

<PROJECT>_<PATH>_<FILE>_H_.

- - -

To guarantee uniqueness, they should be based on the full path in a project's source tree. For example, the file foo/src/bar/baz.h in project foo should have the following guard:

-
#ifndef FOO_BAR_BAZ_H_
 #define FOO_BAR_BAZ_H_
@@ -436,14 +431,11 @@ 
Names and Order of Includes

 
   
  • A blank line
    • 
 
-  
    
   
  • Other libraries' .h files.
    • 
 
   
  • A blank line
    • 
-  
    
 
-  
  • 
-  Your project's .h
+  
  • Your project's .h
   files.
    • 
 
 
@@ -958,7 +950,7 @@ 
    Common patterns
    
 
    Func({42, 3.14});  // Error
    -This kind of code isn't technically an implicit conversion, but the -language treats it as one as far as explicit is concerned. +

    This kind of code isn't technically an implicit conversion, but the +language treats it as one as far as explicit is concerned.

    @@ -2108,18 +2094,12 @@

    cpplint

    positives and false negatives, but it is still a valuable tool.

    - - -

    Some projects have instructions on how to run cpplint.py from their project tools. If the project you are contributing to does not, you can download cpplint.py separately.

    -
    - -

    Other C++ Features

    @@ -2133,9 +2113,9 @@

    Rvalue References

    objects. The syntax is similar to traditional reference syntax. For example, void f(std::string&& s); declares a function whose argument is an -rvalue reference to a std::string.

    +rvalue reference to a std::string.

    -

    When the token '&&' is applied to +

    When the token && is applied to an unqualified template argument in a function parameter, special template argument deduction rules apply. Such a reference is called forwarding reference.

    @@ -2227,7 +2207,7 @@

    Friends

    Friends extend, but do not break, the encapsulation boundary of a class. In some cases this is better than -making a member public when you want to give only one +making a member public when you want to give only one other class access to it. However, most classes should interact with other classes solely through their public members.

    @@ -2243,14 +2223,10 @@

    Exceptions

    nested functions, without the obscuring and error-prone bookkeeping of error codes. - - -
  • Exceptions are used by most other modern languages. Using them in C++ would make it more consistent with Python, Java, and the C++ that others are familiar with.
    • -
  • Some third-party C++ libraries use exceptions, and turning them off internally makes it harder to @@ -2533,8 +2509,8 @@

    Casting

    initialization for conversion of arithmetic types like int64_t y = int64_t{1} << 42. Do not use cast formats like (int)x unless the cast is to -void. You may use cast formats like `T(x)` only when -`T` is a class type.

    +void. You may use cast formats like T(x) only when +T is a class type.

    C++ introduced a @@ -2797,7 +2773,7 @@

    Use of const

  • Declare methods to be const unless they alter the logical state of the object (or enable the user to modify - that state, e.g., by returning a non-const reference, but that's + that state, e.g., by returning a non-const reference, but that's rare), or they can't safely be invoked concurrently.
    • @@ -2850,9 +2826,9 @@

    Use of constexpr

    calls.

    -

    Prematurely marking something as constexpr may cause +

    Prematurely marking something as constexpr may cause migration problems if later on it has to be downgraded. -Current restrictions on what is allowed in constexpr +Current restrictions on what is allowed in constexpr functions and constructors may invite obscure workarounds in these definitions.

    @@ -3746,9 +3722,6 @@

    Boost

    - - -

    In order to maintain a high level of readability for all contributors who might read and maintain code, we only allow an approved subset of Boost features. @@ -3821,10 +3794,6 @@

    Boost

    We are actively considering adding other Boost features to the list, so this list may be expanded in the future.

    -
    - - -

    Other C++ Features

    @@ -3918,7 +3887,7 @@

    Aliases

    Like other declarations, aliases declared in a header file are part of that header's public API unless they're in a function definition, in the private portion of a class, - or in an explicitly-marked internal namespace. Aliases in such areas or in .cc files are + or in an explicitly-marked internal namespace. Aliases in such areas or in .cc files are implementation details (because client code can't refer to them), and are not restricted by this rule.

    @@ -3979,8 +3948,8 @@

    Aliases

    } // namespace mynamespace -

    However, local convenience aliases are fine in function definitions, private sections of - classes, explicitly marked internal namespaces, and in .cc files:

    +

    However, local convenience aliases are fine in function definitions, private sections of + classes, explicitly marked internal namespaces, and in .cc files:

    // In a .cc file
 using ::foo::Bar;
@@ -4202,7 +4171,7 @@ 
    Struct Data Members
    
 
 
    Constant Names
    
 
-
    Variables declared constexpr or const, and whose value is fixed for
+
    Variables declared constexpr or const, and whose value is fixed for
 the duration of the program, are named with a leading "k" followed
 by mixed case. Underscores can be used as separators in the rare cases
 where capitalization cannot be used for separation. For example:
    
@@ -4242,10 +4211,10 @@ 
    Function Names
    
 
 
    Namespace Names
    
 
-Namespace names are all lower-case, with words separated by underscores.
+
    Namespace names are all lower-case, with words separated by underscores.
 Top-level namespace names are based on the project name
 . Avoid collisions
-between nested namespaces and well-known top-level namespaces.
+between nested namespaces and well-known top-level namespaces.
    
 
 
    The name of a top-level namespace should usually be the
 name of the project or team whose code is contained in that
@@ -4374,26 +4343,19 @@ 
    Comment Style
    
 
 
    File Comments
    
 
-
    
 
    Start each file with license boilerplate.
    
-
    
 
 
    File comments describe the contents of a file. If a file declares,
 implements, or tests exactly one abstraction that is documented by a comment
 at the point of declaration, file comments are not required. All other files
 must have file comments.
    
 
-
    Legal Notice and Author
-Line
    
-
+
    Legal Notice and Author Line
    
 
-
-
    
 
    Every file should contain license
 boilerplate. Choose the appropriate boilerplate for the
 license used by the project (for example, Apache 2.0,
 BSD, LGPL, GPL).
    
-
    
 
 
    If you make significant changes to a file with an
 author line, consider deleting the author line.
@@ -4455,7 +4417,7 @@ 
    Function Declarations
    
 preceding it that describe what the function does and how to use
 it. These comments may be omitted only if the function is simple and
 obvious (e.g., simple accessors for obvious properties of the class).
-Private methods and functions declared in `.cc` files are not exempt.
+Private methods and functions declared in .cc files are not exempt.
 Function comments should be written with an implied subject of
 This function and should start with the verb phrase; for example,
 "Opens the file", rather than "Open the file". In general, these comments do not
@@ -4652,8 +4614,8 @@ 
    Don'ts
    
 }
    -Self-describing code doesn't need a comment. The comment from -the example above would be obvious: +

    Self-describing code doesn't need a comment. The comment from +the example above would be obvious:

    if (!IsAlreadyProcessed(element)) {
   Process(element);
@@ -4699,14 +4661,10 @@ 
    TODO Comments
    
 a TODO with a name, it is almost always your
 name that is given.
    
 
-
-
-
    
 
    // TODO(kl@gmail.com): Use a "*" here for concatenation operator.
 // TODO(Zeke) change this to use relations.
 // TODO(bug 12345): remove the "Last visitors" feature.
 
    
-
    
 
 
    If your TODO is of the form "At a future
 date do something" make sure that you either include a
@@ -4728,26 +4686,18 @@ 
    Formatting
    
 they can all read and understand
 everyone's code easily.
    
 
-
-
-
    
 
    To help you format code correctly, we've created a
 
 settings file for emacs.
    
-
    
 
 
    Line Length
    
 
 
    Each line of text in your code should be at most 80
 characters long.
    
 
-
-
-
    
 
    We recognize that this rule is
 controversial, but so much existing code already adheres
 to it, and we feel that consistency is important.
    
-
    
 
 
    
 
    Those who favor  this rule
@@ -5211,7 +5161,6 @@ 
    Loops and Switch Statements
    
 
 
    
 
-
    
 
    switch (var) {
   case 0: {  // 2 space indent
     ...      // 4 space indent
@@ -5226,7 +5175,6 @@ 
    Loops and Switch Statements
    
   }
 }
 
    
-
    
 
 
    Fall-through from one case label to
 another must be annotated using the
@@ -5327,9 +5275,10 @@ 
    Pointer and Reference Expressions
    
 
-It is allowed (if unusual) to declare multiple variables in the same
+
    It is allowed (if unusual) to declare multiple variables in the same
 declaration, but it is disallowed if any of those have pointer or
-reference decorations. Such declarations are easily misread.
+reference decorations. Such declarations are easily misread.
    
+
 
    // Fine if helpful for readability.
 int x, y;
 
    
@@ -5711,9 +5660,6 @@ 
    Exceptions to the Rules
    
 However, like all good rules, these sometimes have exceptions,
 which we discuss here.
    
 
-
-
-
    
 
    Existing Non-conformant Code
    
 
 
    You may diverge from the rules when dealing with code that
@@ -5728,10 +5674,6 @@ 
    Existing Non-conformant Code
    
 the code. Remember that consistency includes
 local consistency, too.
    
 
-
    
-
-
-
 
    Windows Code
    
 
 
     Windows