A<int,60> array[100]; 10060sizeof(int)

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1 \ Y 1 Q Y Y 1 Template! "# & ')4,65')(754+8$')901:$;1$,<9=' $%!& ')( *+,)-0/ 132+'% Template file Ah: <class T1, class T2 T1 _d; T2 _c; ; A<double, int a; 1+@-,<P=$ & ')4D,65')(7G H/$,I& ')9JLM&-&,)% =$;N<2 ')* file Ah: <class T, int size T _array[size]; $ %?& ')(@*+,)-AB/ 1C2D+E'% F A<double,70 a1; A<double,100 a2; &ER5J, WRX $%7S=LL+8$R')90+@1C( G@')'<FT,)/8$R'<FU%EFV&ER5 & ')'+R5M% 5'I$ *1 Y double 18, 1:'1:' $% [ XRX $%ZSJLJ+8$')90+ 13( G@')'<FT,)/8$R'<FU%EF 70*sizeof(double) a1 sizeof double 1'1:' $% 100*sizeof(double) a2 sizeof 1/:FT181:B,)%1C2/CFU,<2 9J*I$%+$;&/ A<int,60 array[100]; $ %Z2D,)/E')=G@$ 2+EB,)-& ')( G ')'<FU,)/8$%7S=LL+82 =')^0' & ')2F S=J+ 13$]M,<^0G,<' 100*60*sizeof(int) 2@'+E*)')PH1I^0GD1 FV& '<^=FU+7,<*)')'18&/ & ')J(+L5M_L')4D,)1$;N<2@')*:/$`1:$/82D,)/E')JG $ A,<$RP0,)-1:'1:':1+ 1:*,<=a@/@1CP0,<GD1C2@0,)%EFVN<')')^0$;1:'1C0%E5L/8'/ default S=J+8$% ctor <typename T, T val class A { void foo() { std::cout << val << std::endl; ; A<int,7 a; 1+ -,<PJ$ & P0,<G7( *+@,)-A0/84D,65')(+82D,<'1:$b$9='TS=L;(@*+,)-AB/ 1

2 ) ; E ; ; ; G E A<char,'h' b; // A<char,78 c; // compilation error afoo(); bfoo(); 7 h 4 1 ' ) =!0 <!$# 8 8* &:,8 1 default file Ah: <class T = double, int size = 50 T _array[size]; ; A< d; // similar to: A<double,50 A<int h; // similar to: A<int,50 A<float,70 z; % 0/*1 )2 & 354!6'! * &:,8 1 3 default "!$# &%('*),+default 3 %('*=),+" 4 + A 4! C4!</ '( &4 B 8@'D) 1 1 B 3 file Ah: Type _data; A(Type data) : _data(data) { bool isbegger(type data); ; specialization - +0) / 4 -?8@) ) 1 A(1B 4 ' # <class Type bool A<Type::isBegger(Type data) { return data _data; #include Ah A<char* a( hi ); std::cout << aisbigger( bye ); 3LJ!$# 3DJ!# %%() ) 3@) -H-I),8 3D+0) / % % 0! %-F%!"/* %(' E _data 86) M)!"A '*%N86), data A 8@'D4@%-F: )!<" M -8@) isbigger() '*) / '*%P 3L86)2-Q),8 4@%%R 4 1 8@3@' 73S4 "!$# %! 7T@' hi! 8@) %R ),+0=(: %('D%*M B/ ),+$-?8@)Q%R %P8@)2-Q),8 %P8 %() ) 3*8 % 0/*1 )2 "% E : -8 U! =) /* T / &% ) ) 3@%V% %R863S) 1 0! 8!<A %R8 %P+0) / %P8U- isbigger() 8 -F) 1 73S% 1 ) ) %(3 bye!< -?T 2

3 & 4 H : H : H H! "! #$ #%'&()!* + ",- % file Ah (/0 123/ ): bool A<char*::isBigger(char *data) { return strcmp(data, _data) 0; 4 56&7 %8 99& A<int ai(5); A<char* as( hi ); aiisbigger(7); // generic isbigger() asisbigger( bye ); // specific isbigger() specialization #include <stringh char* %;<! = % #%+%; =!8 I #+J +%; CB8# " &(,- %$B!%DBEFG$ 8 % 9@ $ -#$CB A $ & # 9 %;<I#@ FG, ;F ; specialization matching N< ÖLBA%8 " A<String specialization FG ";"L +7 M ;$L B# L% %R 9 ;S -! # HQP global function E,*E 9"E'&7 EF+ %; ;? ;9 A &-@ operator << "99 L - %N; SLB88&( ; %6 9,& +%; <class Type void foo(type d) { H H foo(5); // the function foo(int) will be expand and called foo(55); // the function foo(double) will be expand and called foo(21); // the function foo(double) will be called but will not be expand again int i = 5; foo(&i); // the function foo(int*) will be expand and called (Type = int* ) 88@A E!VB &+7$ #,FGLF # ;F; <class Type void foo(type* p) { int d; foo(&d); // foo(int *) will be expand and called (Type = int) ;F ; L $ CB! $L"99 9@('+%; #* " Type 9F, U&-@ - $ 8@ M!VB &+7$ +%; #* NCB8#<& & '' #%& B &-+7 W!! XB &-+7 +%; 9 % &Y999 ;F; 3

4 A #include "LinkedListh" <typename T void foo1(linkedlist<t* list) { <typename T void foo2(linkedlist<linkedlist<t* list) { LinkedList<int* list; LinkedList<LinkedList<int* ll; foo1(list); // T = int foo1(ll); // T = LinkedList<int foo2(ll);; // T = int! " # $! '!*" &, - / & 0 & ) 12 3#! % '&(!)*") & % ) 2 2")55 &4! "* & &4 <class T1, class T2 void foo(t1 t) { T2 data; foo(5); // T2 =?? "! foo() <class T1, class T2 void foo(t2 t2, T1 t1) { T2 data; #! &(!)*") & 1 T2 foo()! "/, & / 0 9 &4:!*<, & - ; / " & T2 ") & & 2-!! %?,, &( #!) & & : = )9 & - compile-time polymorphism Templates 9 = =7 polymorphism -5< B "! $,=C D- / D & :! )!3?, & %# 2 0 1#! /!C# 2 : /" # / 7 D 0 -# 2# & 78/, & & : C- 9) /,=C; - polymorphism s, : E7? =, : E7 D0 #include <iostream <typename T void foo(t t) { tprint(); // compile time polymorphism polymorphism 4

5 ; void print() { std::cout << "I'm a happy instance of A" << std::endl; class B { void print() { std::cout << "I'm a sad instance of B" << std::endl; ; A a; B b; foo(a); foo(b); #include <iostream run-time-polymorphism s class DataStructure { virtual ostream& tostream(ostream& os) const = 0; ; ostream& operator << (ostream& os, const DataStructure& ds) { return dstostream(os); <typename T class List :public DataStructure { virtual ostream& tostream(ostream& os) const { return os<<"i'm a list of " << T::getType() << std::endl; ; <typename T class Tree : public DataStructure { virtual ostream& tostream(ostream& os) const { return os<<"i'm a tree of " << T::getType() << std::endl; ; static char* gettype() {return "A"; 5

6 N & 3 ; class B { static char* gettype() {return "B"; ; Tree<A ta; Tree<B tb; List<A la; List<B lb; std::cout << ta << tb << la << lb; return 0; '( ) *" +!"#"$% #include <iostream #include "LinkedListh" A BC19*DE2/ 13E249 compile-time run-time, DataStructure -/ #89;:2/<*=?624@ # G #!%)HI6J *"%L%F %I ' ) M virtual void print(ostream& os) const =0; ; ostream& operator << (ostream& os, const A* a) { a-print(os); return os; class B : public A { virtual void print(ostream& os) const { os << "B print"; ; class C : public A { virtual void print(ostream& os) const { os << "C print"; ; B b1,b2; C c1,c2; LinkedList<A* list; listinsert(&b1); listinsert(&c1); listinsert(&c2); listinsert(&b2); std::cout << list << std::endl; %F ' 6

7 ( ( - B print - C print - C print - B print ) *! * + *,- )! "! #%$ & ' * $ /10* :5;"<"//4=*76)=?<A@5B/C0D243"E"/27F 25A24=!@G)H%/10*243AE"F /C0I731)65"@37J A L " M" N! L + ' * '# #include <iostream #include <stdlibh <typename T class Less { bool operator() (const T& t1, const T& t2) const { return t1 < t2; ; <typename T class More { bool operator() (const T& t1, const T& t2) const { return t1 t2; ; class DigitLess { int digitsum(const int& t) const { return t-9*(t/10); // good only for two digits number bool operator() (const int& t1, const int& t2) const { return digitsum(t1) < digitsum(t2); ; <typename T void swap(t& t1, T& t2) { T tmp(t1); t1 = t2; t2 = tmp; <typename DS, typename CMP void sort(ds& ds, const CMP& cmp) { for(int i=0; i<dssize(); i++) for(int j=i+1; j<dssize(); j++) if(cmp(ds[j],ds[i])) swap(ds[j],ds[i]); 7

8 <typename T, int SIZE class Array { T _arr[size]; const T& operator[](int i) const { return _arr[i]; T& operator[](int i) { return _arr[i]; int size() {return SIZE; ; <typename T, int SIZE ostream& operator << (ostream& os, const Array<T,SIZE& arr) { for(int i=0; i<size; i++) os << ' ' << arr[i]; return os << ' '; Array<int,20 ar1; Array<double,20 ar2; for(int i=0; i<20; i++) ar2[i] = ar1[i] = i; sort(ar1,less<int()); sort(ar2,more<double()); std::cout << ar1 << " " << std::endl << ar2 << std::endl; sort(ar1,digitless()); std::cout << ar1 << std::endl;

Before we dive in. Preprocessing Compilation Linkage

Before we dive in. Preprocessing Compilation Linkage Templates Before we dive in Preprocessing Compilation Linkage 2 Motivation A useful routine to have is void swap( int& a, int &b ) int tmp = a; a = b; b = tmp; 3 Example What happens if we want to swap