When the function template encounters a function overload

Demo 1

#include <iostream>using namespace std;//let type parameterization = = =, easy for programmers to encode//generic programming//template tell the C + + compiler I'm going to start generic programming. See T, don't give the wrong error tem Plate <typename t>void Myswap (t &a, t &b) {T c = 0;c = A;a = B;b = c;cout << "Hello ...." I am a template function welcome calll me "<< Endl;} void Myswap (int a, char c) {cout << "a:" << a << "C:" << C << endl;cout << "I am a normal function Welcome to visit "<< Endl;} void Main () {inta = 10;charc = ' z '; Myswap (A, c);//Normal function invocation:  can be implicitly type-cast Myswap (c, a);//Call function template Myswap (A, a);//Function Templates function Invocation (Essence: Type parameterization): Will strictly match by type, does not perform automatic type conversion cout<< "Hello ..." <<endl;system ("pause");

With demo 1 You can get:

function template and common function difference conclusion:

1, function template does not allow automatic type conversion;

2, the ordinary function can be automatic type conversion;

Demo 2

/* Function template does not allow automatic type conversion ordinary functions can be automatic type conversion */#include "iostream" using namespace Std;int max (int a, int b) {cout<< "int max (int A, int b) "<<endl;return a > B?" A:B;} Template<typename t>t Max (t A, T B) {cout<< "T Max (t A, T b)" <<endl;return a > B? a:b;} Template<typename t>t Max (t A, T B, t C) {cout<< "T Max (t A, T B, t C)" <<endl;return Max (Max (A, B), c);} void Main () {int a = 1;int B = 2;cout<<max (A, B) <<endl;//When the function template and normal function conform to the call, the normal function cout<<max<> (a , b) <<endl; If the function template is displayed, use the <> type list Cout<<max (3.0, 4.0) <<endl; If a function template produces a better match using a function template Cout<<max (5.0, 6.0, 7.0) <<endl; Heavy Duty Cout<<max (' a ', +) <<endl;  Calling a normal function can implicitly type convert system ("pause"); return;}

Through the analysis of demo 2, we can get:

The calling rules for function templates and common functions:

1, function template can be overloaded like normal functions;

2, C + + compiler takes precedence of common functions;

3, if the function template can produce a better match, then choose the template;

4, the syntax of the empty template argument list can be limited to the compiler only through template matching;

Remember these 4 points and you can avoid a lot of mistakes.

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When the function template encounters a function overload