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// Explore single- and double-throwing techniques
#include <iostream>
using std::cerr;
struct B {
B() { cerr << "make B\n"; }
B( B const & b ) { cerr << "copy B\n"; }
virtual char type() const { return 'B'; };
}; // struct B
struct D : public B {
D() { cerr << "make D\n"; }
D( const D & d ) : B( d ) { cerr << "copy D\n"; }
virtual char type() const { return 'D'; };
}; // struct D
#define single( obj ) \
cerr << "\nsingle( " #obj " )\n"; \
const B & ref = obj; \
throw ref;
#define double( obj ) \
cerr << "\ndouble( " #obj " )\n"; \
try { throw obj; } \
catch ( const B & x ) { throw; }
void f( void g() ) {
try { g(); }
//catch( D const & x ) { cerr << "Caught D is " << x.type() << '\n'; }
catch( B const & x ) { cerr << "Caught B is " << x.type() << '\n'; }
}
void test1() { double( B() ); }
void test2() { double( D() ); }
void test3() { single( B() ); }
void test4() { single( D() ); }
int main() {
cerr << "\nTesting double throws:\n";
f( test1 );
f( test2 );
cerr << "\nTesting single throws:\n";
f( test3 );
f( test4 );
}
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