Function template, function template overload, variable parameter template, function template override, data exchange through reference

Function template, function template overload, variable parameter template, function template override, data exchange through reference
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1. function templates are beginner. If you want to use a template, You need to instantiate it. The instantiation method is to add <数据类型>

# Include

// Function templates can be used to optimize and reload types, which will be overwritten by type

// If you still want to use the template function, you need to instantiate it.

Template

Tadd (Ta, Tb)

{

Std: cout <"T add" <

Returna + B;

}

Intadd (inta, intb)

{

Std: cout <"int add" <

Returna + B;

}

Voidmain ()

{

Inta = 10, B = 20;

Doubledb1 = 10.9, db2 = 10.8;

Add (db1, db2 );

Add (a, B );

// Added It is equivalent to instantiation. The template is called.

Add (A, B );

Std: cin. get ();

}

The running result is as follows:

2. template reload. The template reload will automatically match according to the data type. <喎?http: www.bkjia.com kf ware vc " target="_blank" class="keylink"> Vcd4kcjxwiggfsawdupq = "left"> # include

# Include

Usingstd: array;

Template

Voidshowarray (array Myarray, intn)

{

Usingnamespacestd;

Cout <"TTTTT" <

For (inti = 0; I

{

Cout <

}

Cout <

}

Template

Voidshowarray (array Myarray, intn)

{

Usingnamespacestd;

Cout <"T *" <

For (inti = 0; I

{

Cout <* myarray [I] <"";

}

Cout <

}

Voidmain ()

{

Array Intarray = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };

Array Pintarray;

For (inti = 0; I <10; I ++)

{

Pintarray [I] = & intarray [I];

}

Array Ppintarray;

For (inti = 0; I <10; I ++)

{

Ppintarray [I] = & pintarray [I];

}

Showarray (intarray, 10 );

Showarray (pintarray, 10 );

Showarray (ppintarray, 10 );

Std: cin. get ();

}

The running result is as follows:

3. Variable Parameter templates for common functions

# Include

// The General Variable Parameter template processes an unlimited number of parameters and processes different types of parameters

// Empty function, interface, used to end recursion applies to the new version of the Compiler

Voidshowall (){}

Template

Voidshowall (constT & value, constArgs &... args)

{

Std: cout <value <

Showall (args...); // continue to pass

}

// The design can modify the T & value, Args &... args of the original data

// The design can modify the copy T value, Args... args

// The original data cannot be modified in the design, and the copy const T value and const Args... args cannot be modified.

// The original data referenced by the design cannot be modified by const T & value, const Args &... args

Voidmain ()

{

Intnum1 = 10, num2 = 9, num3 = 11;

Doubledb1 = 10.8, db2 = 10.9;

Charstr [40] = "yincheng ";

Charch = 'a ';

Showall (num1 );

Std: cout <"\ n ";

Showall (num1, num2, num3 );

Std: cout <"\ n ";

Showall (db1, db2, num1, ch );

Std: cout <"\ n ";

Showall (db1, db2, num1, ch, str );

Std: cin. get ();

}

Run the following command:

4. Function template coverage and parameter swapping

# Include

// The function template is universal and can be optimized based on its own data type.

// The struct and class can be directly initialized only when there is no private variable.

// All members are public types and can be assigned values for initialization.

Structinfo

{

Charname [40];

Doubledb;

Intdata;

};

Template

Voidswap (T & a, T & B)

{

Std: cout <"General function template" <std: endl;

Ttemp =;

A = B;

B = temp; // exchange variable

}

// The template is empty, the parameter type is specified, and the type of the function template is overwritten.

// Template <> // optional

Voidswap (info & info1, info & info2)

{

Std: cout <"special function template" <std: endl;

// You can use a template to achieve general purpose and optimize your own data types.

Infotemp = info1;

Info1 = info2;

Info2 = temp;

}

Voidmain ()

{

Infoinfo1 = {"tuzuoquan", 20.9, 10 };

Infoinfoo2 = {"quanzuotu", 9.2, 1 };

Swap (info1, info2 );

Std: cout <info1.name <info1.db <info2.data <std: endl;

Std: cout <info2.name <info2.db <info2.data <std: endl;

Std: cin. get ();

}

Running result:

5. Implement parameter swapping by referencing

# Include

// The function template is universal and can be optimized based on its own data type.

// The struct and class can be directly initialized only when there is no private variable.

// All members are public types and can be assigned values for initialization.

Template

Voidswap (T & a, T & B)

{

Std: cout <"General function template" <std: endl;

Ttemp =;

A = B;

B = temp; // exchange variable

}

Voidmain ()

{

Intnum1 = 100;

Intnum2 = 10;

Swap (num1, num2); // exchange

Std: cout <num1 <"" <

Char character = 'Z ';

Char ch2 = 'a ';

// Note: You must specify the template to use. <类型名称>

Swap (Ch2 );

Std: cout <condition <"" <

Std: cin. get ();

}

6. Variable Parameter templates

# Include

# Include

Voidshowall () {}// reserve one

Template

Voidshow (Tt ,...)

{

Std: cout <t <

}

Template

Voidshowall (Tt, Args... args)

{

Std: cout <t <

Showall (args ...);

}

Voidmain ()

{

Intnum1 = 10, num2 = 9, num3 = 11;

Doubledb1 = 10.8, db2 = 10.9;

Charstr [40] = "yincheng ";

Charch = 'a ';

Show (num1 );

Showall (num2, num3 );

Showall (num2, num3, num1, str, ch );

Std: cin. get ();

}

The running result is as follows: