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- Use boost::addressof instead of &

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- Remove nullptr from test
- add boost::typeindex::bad_runtime_cast, remove std::bad_cast
This commit is contained in:
Chris Glover
2016-08-21 11:01:26 -04:00
parent 9cd218bbc4
commit 3bb646d19b
3 changed files with 72 additions and 47 deletions
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38
examples/runtime_cast.cpp
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@@ -45,32 +45,44 @@ int main() {
C c;
A* a = &c;
if(C* cp = boost::typeindex::runtime_cast<C*>(a))
std::cout << "Yes, a points to a C." << '\n';
else
if(C* cp = boost::typeindex::runtime_cast<C*>(a)) {
std::cout << "Yes, a points to a C: "
<< a << "->" << cp << '\n';
}
else {
std::cout << "Error: Expected a to point to a C" << '\n';
}
if(E* ce = boost::typeindex::runtime_cast<E*>(a))
std::cout << "Error: Expected a to not points to an E." << '\n';
else
if(E* ce = boost::typeindex::runtime_cast<E*>(a)) {
std::cout << "Error: Expected a to not points to an E: "
<< a << "->" << ce << '\n';
}
else {
std::cout << "But, a does not point to an E" << '\n';
}
E e;
C* cp = &e;
if(D* dp = boost::typeindex::runtime_cast<D*>(cp))
std::cout << "Yes, we can cross-cast from a C* to a D* when we actually have an E." << '\n';
else
C* cp2 = &e;
if(D* dp = boost::typeindex::runtime_cast<D*>(cp2)) {
std::cout << "Yes, we can cross-cast from a C* to a D* when we actually have an E: "
<< cp2 << "->" << dp << '\n';
}
else {
std::cout << "Error: Expected cp to point to a D" << '\n';
}
/*`
Alternatively, we can use runtime_pointer_cast so we don't need to specity the target as a pointer.
This works for smart_ptr types too.
*/
A* ap = &e;
if(B* bp = boost::typeindex::runtime_pointer_cast<B>(ap))
std::cout << "Yes, we can cross-cast and up-cast at the same time." << '\n';
else
if(B* bp = boost::typeindex::runtime_pointer_cast<B>(ap)) {
std::cout << "Yes, we can cross-cast and up-cast at the same time."
<< ap << "->" << bp << '\n';
}
else {
std::cout << "Error: Expected ap to point to a B" << '\n';
}
return 0;
}