C ++ templates Note 3 overload function template (additional)

# Include <iostream> <br/> # include <cstring> <br/> # include <string> </P> <p> // maximum of two values of any type <br/> template <typename T> <br/> inline t const & MAX (T const &, t const & B) <br/>{< br/> return a <B? B:; <br/>}</P> <p> // maximum of two pointers <br/> template <typename T> <br/> inline T * const & MAX (T * const &, T * const & B) <br/>{< br/> return * A <* B? B:; <br/>}</P> <p> // maximum of two C-strings <br/> inline char const * const & MAX (char const * const &, <br/> char const * const & B) <br/>{< br/> return STD: strcmp (a, B) <0? B: A; <br/>}</P> <p> int main () <br/>{< br/> int A = 7; <br/> int B = 42; <br/>: max (a, B); // max () for two values of Type int </P> <p> STD: String S = "hey"; <br/> STD: String T = "you "; <br/>: max (S, T); // max () for two values of Type STD :: string </P> <p> int * P1 = & B; <br/> int * P2 = & A; <br/>: max (P1, P2 ); // max () for two pointers </P> <p> char const * S1 = "David"; <br/> char const * S2 = "Nico "; <br/>: max (S1, S2 ); // Max () for two C-strings <br/>}</P> <p>/* <br/> in all the above overloaded implementations, we all pass each real parameter through reference. When reloading the function template, it is best to change only the content that needs to be changed! <Br/> therefore, inline char const * const & MAX (char const * const & A, char const * const & B) <br/> */</P> <p> # include <iostream> <br/> # include <cstring> <br/> # include <string> </P> <p> // maximum of two values of any type (call-by-Reference) <br/> template <typename T> <br/> inline t const & MAX (T const & A, T const & B) <br/>{< br/> return a <B? B: A; <br/>}</P> <p> // maximum of two C-strings (call-by-value) <br/> inline char const * max (char const * a, char const * B) <br/> {<br/> return STD: strcmp (A, B) <0? B: A; <br/>}</P> <p> // maximum of three values of any type (call-by-Reference) <br/> template <typename T> <br/> inline t const & MAX (T const & A, T const & B, T const & C) <br/> {<br/> return max (a, B), c); // error, if Max (A, B) uses call-by-value <br/>}</P> <p> int main () <br/>{< br/>: max (7, 42, 68); // OK </P> <p> const char * S1 = "Frederic"; <br/> const char * S2 = "Anica "; <br/> const char * S3 = "Lucas"; <br/>: max (S1, S2, S3 ); // error </P> <p >}< br/>/* <br/> note that calling return max (a, B), c) is incorrect! For C-string, max (a, B) generates a new temporary local value. This value may be returned by the Max function outside of China as a reference, this will cause invalid references to be returned !! <Br/> the possibility of this error is only possible, not inevitable! Inline t const & MAX (T const & A, T const & B, T const & C) returns a reference! <Br/> */</P> <p> template <typename T> <br/> inline t const & MAX (T const & A, T const & B) <br/>{< br/> return a <B? B:; <br/>}</P> <p> // maximum of three values of any type <br/> template <typename T> <br/> inline t const & MAX (t const &, t const & B, T const & C) <br/>{< br/> return max (a, B), c ); // uses the template version even for ints <br/>}// because the following declaration comes <br/> // too late: <br/> // maximum of two int values <br/> inline int const & MAX (INT const & A, int const & B) <br/> {<br/> Return a <B? B:; <br/>}</P> <p>/* <br/> the declaration of all overloaded versions of the function should be prior to the position where the function is called <br/> */