C++Primer第16章-模板与泛型编程-部分选做习题答案.doc

16章 部分选做习题 16.1编写一个模板返回形参的绝对值，至少用三种不同类型的值调用模板。注意：在16.3节讨论编译器怎样处理模板实例化之前，你应该将每个模板定义和该模板的所有使用放在同一文件中。 // 16.1_template.cpp : 定义控制台应用程序的入口点。 // #include stdafx.h #include iostream template typename T inline T abs( T tVal) { return tVal 0 ? tVal : -1*tVal; } int _tmain(int argc, _TCHAR* argv[]) { std::cout \n\tabs( false ) is:\t abs(false) std::endl \n\tabs( -3 ) is:\t\t abs( -3 ) std::endl \n\tabs( -8.6 ) is:\t\t abs( -8.6 ) std::endl; system(pause); return 0; } 16.2 编写一个函数模板，接受一个ostream引用和一个值，将该值写入流。用至少四种不同类型调用函数。通过写至cout、写至文件和写至stringstream来测试你的程序。 // 16.2_template.cpp : 定义控制台应用程序的入口点。 // #include stdafx.h #include iostream #include ostream #include fstream #include sstream #include cassert using namespace std; template typename T inline void testOstream( ostream os, T tVal ) { os tVal; } int _tmain(int argc, _TCHAR* argv[]) { // cout cout Test of testOstream( cout, 6 ):\t; testOstream( cout, 6 ); cout \n Test of testOstream( cout, true ):\t; testOstream( cout, true ); cout \n Test of testOstream( cout, 8.6 ):\t; testOstream( cout, 8.6 ); cout \n Test of testOstream( cout, \Good!\ ):\t; testOstream( cout, Good! ); cout endl; // ofstream ofstream outfile; outfile.open(testOf_Ofstream.txt); assert( outfile ); if ( !outfile ) { return NULL; } cout \n\tTest of ofstream, Please check the file just create.\n; testOstream(outfile, \n Test of testOstream( outfile, 6 ):\t); testOstream( outfile, 6 ); testOstream(outfile, \n Test of testOstream( outfile, true ):\t); testOstream( outfile, true ); testOstream(outfile, \n Test of testOstream( outfile, 8.6 ):\t); testOstream( outfile, 8.6 ); testOstream(outfile, \n Test of testOstream( outfile, \Good!\ ):\t); testOstream( outfile, Good! ); outfile.close(); cout endl; // stringstream stringstream oss; cout \n Test of testOstream( oss, 6 )/( oss, true )/( oss, 8.6 )/( oss, \Good!\): endl; testOstream( oss, 6 ); testOstream( oss, \n ); testOstream( oss, t