K&R风格VSMS风格

(1)书写结构

k&r风格: 缩进一个水平制符,k&r提倡8格.左花括号紧接其后不另起一行(函数体的左括号除外).
if(...) {
        ...;
        ...;
} else if(...) {
        ...;
        ...;
} else {
        ...;
        ...;
}

while(...) {
        ...;
        ...;
}

do {
        ...;
        ...;
}while(...);

for(...;...;...) {
        ...;
        ...;
}

typedef {
        ...;
        ...;
        ...;
}abc;

class abc {
        ...;
        ...;
        ...;
};

ms vc++风格: 缩进一个水平制符,vc的水平制符相当4个空格.
if(...)
{
    ...;
    ...;
}
else if(...)
{
    ...;
    ...;
}
else
{
    ...;
    ...;
}

while(...)
{
    ...;
    ...;
}

do
{
    ...;
    ...;
}while(...);

typedef
{
    ...;
    ...;
    ...;
}abc;

class abc
{
    ...;
    ...;
    ...;
};

坚持k&r风格的开发人员认为将左花括号单独占一行浪费了行数,使代码稀疏不够紧凑.只要右花括跟条件控制关键字if,while,do,for等并列即已很清晰.缩进制表符相当于8个空格,这样层次清晰,4格不够清晰.

坚持ms风格的开发人员认为左花括号紧接其后不另起一行而函数体的左括号却另起一行,是一种怪异的不一致性.缩进8格太多,缩进层次多了会使一些代码跑出屏幕.

(2)命名法
k&r风格: 讲究简短清爽.单词一致使用小写;一个单词超过8个字符的使用缩写;一个名字中包含多个单词则用下划线隔开它们.

BOOL empty;
int num_element;
void get_element();
class stack;
class seq_stack;
struct student;
object obj;
dialog dlg;
int object::cls_id;
int tmp;
int i, j;

ms风格: 讲究表意明确.使用匈牙利法给名字加类型前缀;每个单词第一个字母以大写开头;相对前者更容易冗长,也有少部分地方借鉴于k&r风格.

BOOL bIsEmpty;
int dwNumberOfElements;
void GetElement();
class IStack;
class CSequenceStack;
struct SStudentInfo;
CBaseObject cBaseObject;
CBaseDialog cBaseDialog;
int CBaseObject::m_dwClassID;
//也有少部分借鉴于k&r的简约风格
int tmp;
int i, j;

坚持ms风格的人认为k&r风格的变量,结构和很多标识符出现在一起时,有时人会分不清标识符是函数内的成员还是普通变量,或者不知道变量,结构还是类.

坚持k&r风格的人认为微软的所谓"表意明确"和匈牙利类型命名法是纯粹自找脑损伤的表现.好的名字本来就不应该让程序员看不懂是什么类型.又何尝要加匈牙利类型前缀,并讽刺匈牙利类型前缀是写给编译器看的.

(3)总结
k&r风格,历史悠久,而且有众多友好的开源兄弟,如linux内核风格,gnu编码规范,它们都跟k&r基本相同.如果要写开源代码,使用k&r可能会更受人欢迎.不少坚持k&r风格的开发人员认为k&r风格是老字号,是C语言发明人提出国际标准化组织制定的风格.因此一些开发者认为ms风格不够正统.

ms风格是这几年推向MS外部开发人员的后起之秀,凭着微软的软件巨无霸的实力,迅速风靡开来.随着Visual C++,MFC在开发市场推广和普及,越来越多的开发人员逐渐接受了ms风格.不少坚持ms风格的开发人员认为k&r风格已过时,编程规范应该与时俱进.

初探boost之noncopyable学习笔记

noncopyable

功能

同意程序轻松实现一个不可复制的类。

需包括头文件

#include<boost/noncopyable.hpp>     或

#include<boost/utility.hpp>

原理

在c++定义一个类时。假设不明白定义复制构造函数和复制赋值操作符。编译器会为我们自己主动生成这两个函数。

比如

class empty_class{ } ；

实际上类似于

class empty_class

{

public:

    empty_class(const empty_class &){...}

    empty_class & operator=(const empty_class &){...}

};

但有时候我们不要类的复制语义，希望禁止复制类的实现。比較常见的做法就是私有化复制构造函数和赋值操作符，

手写代码也非常easy。如：

class do_not_copy

{

private:

    do_not_copy(const do_not_copy &);

    void operator=(const do_not_copy &);

};

但假设程序中有大量这种类，反复写代码也是非常麻烦的，解决方法也不够优雅。

noncopyable为实现不可复制的类提供了简单清晰的解决方式：从 boost::noncopyable 派生就可以。

这里使用默认的私有继承是同意的。显示的写出private或public修饰词也能够。效果同样。

我们定义的子类会自己主动私

有化父类noncopyable的复制构造函数。从而禁止用户从外部訪问复制构造函数和复制赋值函数。

使用方法

以上样例也改写为：

class do_not_copy :boost::noncopyable

{...};

举例

#include<iostream>
#include<boost/utility.hpp>
#include<boost/noncopyable.hpp>

using namespace std;
using namespace boost;

class student:boost::noncopyable
{
public:
    student(int _id):id(_id){};
    int print(){return id;}
private:
    int id;
};

int main()
{
    student st(100);
    cout<<st.print()<<endl;
    student scopy(st);  //报错
    cout<<scopy.print()<<endl;
    return 0;
}

若没有继承noncopyable

输出：

100

100

若继承，如上述代码，在凝视那句開始报错。

 

在 Visual Studio 中使用 EditorConfig 统一代码风格（含原生与插件）

EditorConfig 是一种被各种编辑器广泛支持的配置，使用此配置有助于项目在整个团队中保持一致的代码风格。Visual Studio 2017 开始原生支持 EditorConfig。

本文将介绍 Visual Studio 对 EditorConfig 的支持情况（含原生与插件），并给出符合 .NET 和 C# 约定的 EditorConfig 详细设置。

---

本文内容

• • EditorConfig 的广泛支持
  • Visual Studio 对 EditorConfig 的支持程度
  • 在 Visual Studio 中添加 EditorConfig 配置
  • 在 Visual Studio 中开启 EditorConfig 支持
  • 在 ReSharper 中开启 EditorConfig 支持
  • 效果体验
  • • 附 EditorConfig Language Service 生成的属性集
    • 附 IntelliCode 生成的属性集

EditorConfig 的广泛支持

在 EditorConfig 官网中，贴出了一些可以纯原生无需任何插件支持 EditorConfig 代码风格配置的编辑器：

▲ 原生支持 EditorConfig 的编辑器

然后还贴出了可以通过插件支持的编辑器：

▲ 可以通过插件支持 EditorConfig 的编辑器

EditorConfig 本身只定义了一个核心集，表示所有语言都共同遵循的代码格式规范：EditorConfig 属性的核心集。同时，还有一些其他定义的规范：EditorConfig 的完整属性，不过这里不包括语言特定的规范。

Visual Studio 对 EditorConfig 的支持程度

Visual Studio 2017 开始添加了对 EditorConfig 的原生支持（你当然能在上面看到 Visual Studio 的图标啦）。

原生的 Visual Studio 2017 支持 EditorConfig 属性的核心集和一些语言的特定属性。具体来说，是这一些：

• 核心属性
  • indent_style
  • indent_size
  • tab_width
  • end_of_line
  • charset
  • trim_trailing_whitespace
  • insert_final_newline
  • root
• 语言特定属性
  • 所有 Visual Studio 支持的语言（XML 除外）均支持 EditorConfig 编辑器设置。
  • 此外，EditorConfig 还支持适用于 C# 和 Visual Basic 的代码样式约定和命名约定。

也就是说，当你的项目中存在 EditorConfig 的配置文件 .editorconfig 的时候，Visual Studio 就会应用 EditorConfig 的设置，而且可以适用于多数情况下的编程约定。

Visual Studio 中 .NET 相关语言（C# VB）的 EditorConfig 属性，可以参考 .NET coding convention settings For EditorConfig。

在 Visual Studio 中添加 EditorConfig 配置

Visual Studio 支持 EditorConfig 对编程规范的约束。对于多数开发者来说，不需要安装任何插件的情况下这个编程规范的约束就会生效。

不过，还是需要有一些小伙伴进行编程规范的设置。设置规范可以使用很多个插件，比如 EditorConfig Language Service 和 Visual Studio IntelliCode。当然，前者会更加专业，后者只是因为需要使用到 EditorConfig 的配置，顺便带上了 EditorConfig 的编辑体验。

安装了 EditorConfig Language Service 插件之后，在解决方案上右键，添加 .editorconfig 文件。

▲ 添加 .editorconfig 文件

当然，也许你会发现在我的图中，两个插件都能生成 .editorconfig 文件。EditorConfig Language Service 生成的 .editorconfig 文件是空的，而 IntelliCode 一经添加便提供了丰富的 C# 语言约定的属性设置。不过，IntelliCode 提供的设置多少取决于你目前解决方案中的项目类型，这些属性是从 这里 推断的。

如果你使用 EditorConfig Language Service 生成了 .editorconfig 文件，则可以继续点击小灯泡生成按照微软约定的编程规范：

▲ 生成规范

在 Visual Studio 中开启 EditorConfig 支持

实际上，Visual Studio 一旦检测到 .editorconfig 文件的存在，格式约定就会自动生效。

在 ReSharper 中开启 EditorConfig 支持

一样的，ReSharper 默认是开启了 EditorConfig 配置的检测的，也就是说只要存在 .editorconfig 文件，那么 EditorConfig 也会在 ReSharper 的格式化中生效。

ReSharper 对于 EditorConfig 的支持情况可以参考：Using EditorConfig - Help - ReSharper。

效果体验

我们来看一段风格十分混乱不忍直视的代码：

using System;
using System.Threading.Tasks;

namespace Walterlv.Demo
{
    public static class Program
    {
        [STAThread]
        private static int Main(string[] args)
        {
            var logger = (ILogger)   new Logger();
            var   logger2 = (ILogger)new Logger();
            var managerTask = Task.Run(  () => 
                {
                    var manager = new Manager(logger);
                    manager.Run();
                    return manager;
                });
            var app = new App(managerTask) {

            };
                app.InitializeComponent();
                app.Run();
                return 0;
        }
    }
}

无论你是使用什么方式，最终都能格式化成下面这样：

• 你可以直接输入，在遇到 } 和 ; 的时候就会格式化
• 你可以 Ctrl+V 粘贴，粘贴后直接就是格式化后的代码
• 你可以按下 Ctrl+Alt+Enter（ReSharper），这样整份文档就会格式化
• 你可以按下 Ctrl+K, D（Visual Studio 的 Cleanup），这样也能格式化

using System;
using System.Threading.Tasks;

namespace Walterlv.Demo
{
    public static class Program
    {
        [STAThread]
        private static int Main(string[] args)
        {
            var logger = (ILogger)new Logger();
            var logger2 = (ILogger)new Logger();
            var managerTask = Task.Run(() =>
            {
                var manager = new Manager(logger);
                manager.Run();
                return manager;
            });
            var app = new App(managerTask)
            {

            };
            app.InitializeComponent();
            app.Run();
            return 0;
        }
    }
}

附 EditorConfig Language Service 生成的属性集

[*]
end_of_line = crlf
charset = utf-8-bom
indent_size = 4
insert_final_newline = true
tab_width = 4
trim_trailing_whitespace = true

[*.xml]
indent_style = space

[*.{cs,vb}]
dotnet_sort_system_directives_first = true
dotnet_style_coalesce_expression = true:suggestion
dotnet_style_collection_initializer = true:suggestion
dotnet_style_explicit_tuple_names = true:suggestion
dotnet_style_null_propagation = true:suggestion
dotnet_style_object_initializer = true:suggestion
dotnet_style_parentheses_in_arithmetic_binary_operators = always_for_clarity:silent
dotnet_style_parentheses_in_other_binary_operators = always_for_clarity:silent
dotnet_style_parentheses_in_other_operators = never_if_unnecessary:silent
dotnet_style_parentheses_in_relational_binary_operators = always_for_clarity:silent
dotnet_style_predefined_type_for_locals_parameters_members = true:silent
dotnet_style_predefined_type_for_member_access = true:silent
dotnet_style_prefer_auto_properties = true:silent
dotnet_style_prefer_conditional_expression_over_assignment = true
dotnet_style_prefer_conditional_expression_over_return = true
dotnet_style_prefer_inferred_anonymous_type_member_names = true:suggestion
dotnet_style_prefer_inferred_tuple_names = true:suggestion
dotnet_style_prefer_is_null_check_over_reference_equality_method = true:silent
dotnet_style_qualification_for_event = false:silent
dotnet_style_qualification_for_field = false:silent
dotnet_style_qualification_for_method = false:silent
dotnet_style_qualification_for_property = false:silent
dotnet_style_readonly_field = true:suggestion
dotnet_style_require_accessibility_modifiers = for_non_interface_members:silent

[*.cs]
csharp_indent_case_contents = true
csharp_indent_labels = flush_left
csharp_indent_switch_labels = true
csharp_new_line_before_catch = true
csharp_new_line_before_else = true
csharp_new_line_before_finally = true
csharp_new_line_before_members_in_anonymous_types = true
csharp_new_line_before_members_in_object_initializers = true
csharp_new_line_before_open_brace = all
csharp_new_line_between_query_expression_clauses = true
csharp_preferred_modifier_order = public,private,protected,internal,static,extern,new,virtual,abstract,sealed,override,readonly,unsafe,volatile,async:suggestion
csharp_prefer_braces = true:silent
csharp_prefer_simple_default_expression = true:suggestion
csharp_preserve_single_line_blocks = true
csharp_preserve_single_line_statements = true
csharp_space_after_cast = false
csharp_space_after_colon_in_inheritance_clause = true
csharp_space_after_keywords_in_control_flow_statements = true
csharp_space_around_binary_operators = before_and_after
csharp_space_before_colon_in_inheritance_clause = true
csharp_space_between_method_call_empty_parameter_list_parentheses = false
csharp_space_between_method_call_name_and_opening_parenthesis = false
csharp_space_between_method_call_parameter_list_parentheses = false
csharp_space_between_method_declaration_empty_parameter_list_parentheses = false
csharp_space_between_method_declaration_parameter_list_parentheses = false
csharp_space_between_parentheses = false
csharp_style_conditional_delegate_call = true:suggestion
csharp_style_deconstructed_variable_declaration = true:suggestion
csharp_style_expression_bodied_accessors = true:silent
csharp_style_expression_bodied_constructors = false:silent
csharp_style_expression_bodied_indexers = true:silent
csharp_style_expression_bodied_methods = false:silent
csharp_style_expression_bodied_operators = false:silent
csharp_style_expression_bodied_properties = true:silent
csharp_style_inlined_variable_declaration = true:suggestion
csharp_style_pattern_local_over_anonymous_function = true:suggestion
csharp_style_pattern_matching_over_as_with_null_check = true:suggestion
csharp_style_pattern_matching_over_is_with_cast_check = true:suggestion
csharp_style_throw_expression = true:suggestion
csharp_style_var_elsewhere = true:silent
csharp_style_var_for_built_in_types = true:silent
csharp_style_var_when_type_is_apparent = true:silent

[*.vb]
visual_basic_preferred_modifier_order = Partial,Default,Private,Protected,Public,Friend,NotOverridable,Overridable,MustOverride,Overloads,Overrides,MustInherit,NotInheritable,Static,Shared,Shadows,ReadOnly,WriteOnly,Dim,Const,WithEvents,Widening,Narrowing,Custom,Async:suggestion:suggestion

附 IntelliCode 生成的属性集

# Rules in this file were initially inferred by Visual Studio IntelliCode from the C:UserslvyiWalterlv.Demo codebase based on best match to current usage at 2018/11/20
# You can modify the rules from these initially generated values to suit your own policies
# You can learn more about editorconfig here: https://docs.microsoft.com/en-us/visualstudio/ide/editorconfig-code-style-settings-reference
[*.cs]

#Core editorconfig formatting - indentation

#use soft tabs (spaces) for indentation
indent_style = space

#Formatting - indentation options

#indent switch case contents.
csharp_indent_case_contents = true
#csharp_indent_case_contents_when_block
csharp_indent_case_contents_when_block = false
#indent switch labels
csharp_indent_switch_labels = true

#Formatting - new line options

#place catch statements on a new line
csharp_new_line_before_catch = true
#place else statements on a new line
csharp_new_line_before_else = true
#require finally statements to be on a new line after the closing brace
csharp_new_line_before_finally = true
#require braces to be on a new line for methods, accessors, control_blocks, lambdas, properties, and types (also known as "Allman" style)
csharp_new_line_before_open_brace = methods, accessors, control_blocks, lambdas, properties, types

#Formatting - organize using options

#sort System.* using directives alphabetically, and place them before other usings
dotnet_sort_system_directives_first = true

#Formatting - spacing options

#require a space before the colon for bases or interfaces in a type declaration
csharp_space_after_colon_in_inheritance_clause = true
#require a space after a keyword in a control flow statement such as a for loop
csharp_space_after_keywords_in_control_flow_statements = true
#require a space before the colon for bases or interfaces in a type declaration
csharp_space_before_colon_in_inheritance_clause = true
#remove space within empty argument list parentheses
csharp_space_between_method_call_empty_parameter_list_parentheses = false
#remove space between method call name and opening parenthesis
csharp_space_between_method_call_name_and_opening_parenthesis = false
#do not place space characters after the opening parenthesis and before the closing parenthesis of a method call
csharp_space_between_method_call_parameter_list_parentheses = false
#remove space within empty parameter list parentheses for a method declaration
csharp_space_between_method_declaration_empty_parameter_list_parentheses = false
#place a space character after the opening parenthesis and before the closing parenthesis of a method declaration parameter list.
csharp_space_between_method_declaration_parameter_list_parentheses = false

#Formatting - wrapping options

#leave code block on single line
csharp_preserve_single_line_blocks = true
#leave statements and member declarations on the same line
csharp_preserve_single_line_statements = true

#Style - expression bodied member options

#prefer block bodies for accessors
csharp_style_expression_bodied_accessors = false:suggestion
#prefer block bodies for constructors
csharp_style_expression_bodied_constructors = false:suggestion
#prefer block bodies for indexers
csharp_style_expression_bodied_indexers = false:suggestion
#prefer block bodies for methods
csharp_style_expression_bodied_methods = false:suggestion
#prefer block bodies for properties
csharp_style_expression_bodied_properties = false:suggestion

#Style - expression level options

#prefer out variables to be declared before the method call
csharp_style_inlined_variable_declaration = false:suggestion
#prefer the language keyword for member access expressions, instead of the type name, for types that have a keyword to represent them
dotnet_style_predefined_type_for_member_access = true:suggestion

#Style - implicit and explicit types

#prefer var is used to declare variables with built-in system types such as int
csharp_style_var_for_built_in_types = true:suggestion
#prefer var when the type is already mentioned on the right-hand side of a declaration expression
csharp_style_var_when_type_is_apparent = true:suggestion

#Style - language keyword and framework type options

#prefer the language keyword for local variables, method parameters, and class members, instead of the type name, for types that have a keyword to represent them
dotnet_style_predefined_type_for_locals_parameters_members = true:suggestion

#Style - qualification options

#prefer events not to be prefaced with this. or Me. in Visual Basic
dotnet_style_qualification_for_event = false:suggestion
#prefer fields not to be prefaced with this. or Me. in Visual Basic
dotnet_style_qualification_for_field = false:suggestion
#prefer methods not to be prefaced with this. or Me. in Visual Basic
dotnet_style_qualification_for_method = false:suggestion
#prefer properties not to be prefaced with this. or Me. in Visual Basic
dotnet_style_qualification_for_property = false:suggestion

---

参考资料

• Using EditorConfig settings in Visual Studio - Visual Studio - Microsoft Docs
• .NET coding convention settings For EditorConfig - Visual Studio - Microsoft Docs

---

我的博客会首发于 https://blog.walterlv.com/，而 CSDN 会从其中精选发布，但是一旦发布了就很少更新。

如果在博客看到有任何不懂的内容，欢迎交流。我搭建了 dotnet 职业技术学院 欢迎大家加入。