/Home/TACE/openav/source/seamlessmessage/cpaoflt. O: In function 'cpaoflt: get_m_strprmair () const ':Cpaoflt. cpp :(. Text + 0x0): Multiple definition of 'cpaoflt: get_m_strprmair () const'/Home/TACE/openav/source/seamlessmessage/cpaoflt. O: cpaoflt. cpp :(. Text + 0x0): first defined here
During the compilation process, GCC reports the multiple definition of function errors, mainly including the followin
There are two types of macro definitions: macro definitions without parameters and macro definitions with parameters.
Macro definition without ParametersThe general format of macro definition without parameters is:
# Define macro name string# Define PI 3.1415926Main (){Float area, R;Printf ("Area = % F", pI * r * R );}In the above program, the macro pi is used to replace the string 3.1415926. The advantage
Ask questions:If you have such a template:class test{public: static std::string info;};What is right (by compiling) for several of the following definitions?Template stringtestint>::info ("123"); templatestringTest"123"); templatestringTest:: Info;templatestringtestint>:: info; templatestringtestint>:: info (); templatestringTestIn order not to affect the analysis and judgment, I put the answer color into a relatively light color, the following is the answer:
Template
Template
We are in the program design, always use the definition of variables and variable declarations, but sometimes we are not very clear about the concept, know how it is used, but do not know how to do, the following I simply put their differences are described as follows:
There are two things about the declaration of a variable:(1) One is the need to establish storage space (definition, declaration). For exam
"); Programing in C was fun printf ("Programming" "in C" "is fun" \ n);//programing in C is fun///////////////////////////// Macro definition hasno parameter macro definitionAndwith parameter macro definitionTwo kinds.The general form of a macro definition without parameters is # define identifier character sequence The identifier after # define is called the macro
I. Overview:
1. After a site is created based on the site definition, the related site definition cannot be deleted. After the site set or website wear is complete, the related site definition files are available, deletion will cause the function to fail to run normally.
2. the XML file in 1033 \ XML is the site definitio
In the introduction to the spring IOC container launch, a rough analysis of the launch process of the IOC container was made on the basis of Classpathxmlapplicationcontext, with no detailed description of some of the more complex steps, This article begins with some of the more complex steps that are analyzed. This article analyzes the parsing and loading process of the bean definition of the IOC container based on the Classpathxmlapplicationcontext.
development of function declarations
1 implicit function Declaration implicit function declarationThe main function and the printf function return value type int, if not declared, the compiler default function return value is the INT type C90 standard, this kind of writing enters the process which is gradually discarded (although it was not abolished completely immediately) C99 abolished the implicit function declaration law (remove impli CIT function declaration), omitting the int in front of
Replace macros with inline:
1. Inline functions can be debugged at run time, while macro definitions are not possible;2. The compiler will do security checks or automatic type conversions (with normal functions) on the parameter types of the function, while the macro definition will not;3. The inline function can access the member variables of the class, and the macro definition cannot;4. Declare a member
Detailed description of the definition and execution principle of asynchronous Action under ASP. net mvc, asp. netmvc
The Controller creation Wizard provided by Visual Studio creates a Controller type inherited from the abstract class Controller by default. Such a Controller can only define synchronous Action methods. To define an asynchronous Action method, we must inherit the abstract class AsyncController. This article describes two different async
Matlabsix ways to customize a functionN1, function file + Call Function (command) file: m file to define a custom function separately;N2, function file + sub-function: Defines an m file with multiple custom functions;N3,Inline: No m file, direct definition; N4, anonymous function;N5,syms+subs: No m file, direct definition; N6, String +subs: No m file, directly defined. ------------1 , function Files + calli
1,Use a # Before a parameter in a Preprocessor macro. The Preprocessor converts this parameter to a character array. (Original article: when you put a # Before an argument in a Preprocessor
Macro, The Preprocessor turns that argument into a character array. This,
Combined with the fact that character arrays with no intervening punctuation are concatenated into a single character array, allows you to make a very convenient macro for printing the values of variables during debugging)
# Include "io
(1) inline function (from the third edition of C ++ primer)
In the function declaration or definition, add the keyword inline before the function return type to specify min () as inline.
Inline int min (INT first, int secend ){/****/};
The inline function must be visible to the compiler so that it can expand the function within the call point. Unlike non-inline functions, inline functions must be defined in each text file that calls the function. Of c
I found a small problem when writing a program today, as shown below:
1 #include 2 #include 3 4 using namespace std; 5 template 6 class Node 7 { 8 private: 9 Node10 public:11 T data;12 Node(const T item,Node13 void InsertAfter(Node14 Node15 Node16 };17 18 template19 Node20 21 template22 Node23 {24 return next;25 }26 27 int main(void)28 {29 return 1;30 }
The following error occurs during compilation:
If the default value of the
I studied definitions and declarations in C. The concepts are mainly embodied in functions, that is, declarations only tell the compiler that there is such a thing that there is no specific operation to define functions, the definition is specific to what the function should do.
Then I got confused when I came to C ++ and C #. What should I say about the class? What should I say about the objects of the definitio
[Switch] DEFINE introduction and multi-row macro definition in C language, define multiple lines
[Go] DEFINE introduction and multi-row macro definition in C LanguageTo write a good C language, a beautiful macro definition is very important. Macro definition can help us prevent errors and improve code portability and r
1. Rules and usage resolution for macro definitions(1) The parsing rule of a macro definition is that it is replaced by a preprocessor during the preprocessing phase, and the substitution is unchanged.(2) The macro definition substitution is performed recursively until the replaced value itself is no longer a macro.(3) A correct macro definition of the formula it
Differences between variable definition and Declaration
(Reprinted)
In program design, we always use the definition of variables and the declaration of variables. Sometimes we are not very clear about this concept and know how to use it, but I don't know how it will take for a while. Below I will simply introduce their differences as follows:
There are two scenarios for variable declaration:(1) One is to cr
Macro Definition Learning
(1) Macro names are generally capitalized(2) The use of macros can improve the universality and readability of the program, reduce inconsistencies, reduce input errors and facilitate modification. Example: array size common macro definitions(3) Preprocessing is the processing before compiling, and one of the tasks of compiling is grammar checking, preprocessing does not do grammar checking.(4) No semicolon at the end of
A macro definition is one of the pre-compilation features, pre-compilation, also known as preprocessing, is the preparatory work for the compilation phase. The instructions that handle the beginning of the #, such as the file code that the copy #include contains, #define宏定义的替换, conditional compilation, and so on.Benefits of using macro definitions: Benefits of using Macro definitions: Improves program versatility and readability, reduces inconsistenci
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