Ichthyostega
3caa5cfb03
This resolves a long-standing issue: we could not use proper include paths for test-helper code that was defined alongside the tests. Since some test-helper code must now be relocated into the »Vault«-Layer, I took the opportunity to finally resolve this annoyance. The solution is two-fold * introduce a dedicated test-support library * remove the quirks that were necessary to support some plain-C tests Together, this allows to raise the include-directory by one level, and then to adjust all folder names so that they match the namespace
258 lines
14 KiB
C++
258 lines
14 KiB
C++
/*
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AccessCasted(Test) - verify helper to cast or convert as appropriate
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Copyright (C)
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2008, Hermann Vosseler <Ichthyostega@web.de>
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**Lumiera** is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by the
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Free Software Foundation; either version 2 of the License, or (at your
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option) any later version. See the file COPYING for further details.
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* *****************************************************************/
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/** @file access-casted-test.cpp
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** unit test \ref AccessCasted_test
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*/
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#include "test/run.hpp"
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#include "test/test-helper.hpp"
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#include "lib/access-casted.hpp"
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#include "lib/format-cout.hpp"
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#include "lib/util.hpp"
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#include <utility>
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#include <string>
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using std::move;
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using std::string;
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using std::ostream;
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using util::isSameObject;
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using LERR_(BOTTOM_VALUE);
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using LERR_(WRONG_TYPE);
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namespace util {
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namespace test {
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namespace { // Test fixture...
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struct B {};
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struct D : B {};
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struct E : D
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{
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virtual ~E() {};
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};
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struct X
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{
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char x = 'x';
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};
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struct F
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: X
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, E
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{ };
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ostream& operator<< (ostream& s, const B& b) { return s << "B{} adr="<<&b; }
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ostream& operator<< (ostream& s, const D& d) { return s << "D{} adr="<<&d; }
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ostream& operator<< (ostream& s, const E& e) { return s << "E{} adr="<<&e; }
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ostream& operator<< (ostream& s, const F& f) { return s << "F{} adr="<<&f; }
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}//(End)Test fixture
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/*************************************************************************************************//**
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* @test verify a helper template for accessing values either through conversion or (dynamic) downcast.
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* Typically, this helper is used in value holder containers or variant-like data structures,
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* where the actual type is given at instantiation time of the template and possibly erased.
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*
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* @warning we can not really cover the negative cases, which ought to be rejected by the compiler.
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* These cases have been verified one by one, and are retained commented out. You ought
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* to re-check these cases manually when using a new compiler.
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*/
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class AccessCasted_test : public Test
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{
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virtual void
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run (Arg)
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{
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D d;
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D* pD =&d;
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B* pB =pD;
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D& rD = *pD;
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B& rB = *pB;
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D*& rpD = pD;
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B*& rpB = pB;
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E e;
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E& rE = e;
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F f;
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E& rEF = f;
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E* pEF = &f;
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X* pXF = &f;
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F* pF = &f;
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cout << "can_downcast<B,D> = " << can_downcast<B,D>::value <<endl;
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cout << "can_downcast<B*,D*> = " << can_downcast<B*,D*>::value <<endl;
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cout << "can_downcast<B&,D&> = " << can_downcast<B&,D&>::value <<endl;
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cout << "can_downcast<B&,D*> = " << can_downcast<B&,D*>::value <<endl;
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cout << "can_downcast<B*,D&> = " << can_downcast<B*,D&>::value <<endl;
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cout << "can_downcast<B*&,D*&> = " << can_downcast<B*&,D*&>::value <<endl;
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cout << "can_downcast<D*&,D*&> = " << can_downcast<D*&,D*&>::value <<endl;
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cout << "can_downcast<D*,E*> = " << can_downcast<D*,E*>::value <<endl;
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cout << "can_downcast<E*,F*> = " << can_downcast<E*,F*>::value <<endl;
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cout << "has_RTTI<D*> = " << has_RTTI<D*>::value <<endl;
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cout << "has_RTTI<E*> = " << has_RTTI<E*>::value <<endl;
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cout << "has_RTTI<F*> = " << has_RTTI<F*>::value <<endl;
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cout << "is_convertible<D,D&> = " << std::is_convertible<D,D&>::value <<endl;
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cout << "is_convertible<D&,D> = " << std::is_convertible<D&,D>::value <<endl;
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cout << "can_use_dynamic_downcast<D,D&> = " << can_use_dynamic_downcast<D,D&>::value <<endl;
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cout << "can_use_conversion<D,D&> = " << can_use_conversion<D,D&>::value <<endl;
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cout << "can_use_dynamic_downcast<B*,D*> = " << can_use_dynamic_downcast<B*,D*>::value <<endl;
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cout << "can_use_conversion<D*,B*> = " << can_use_conversion<D*,B*>::value <<endl;
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cout << "can_use_dynamic_downcast<D*&,D*&> = " << can_use_dynamic_downcast<D*&,D*&>::value <<endl;
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cout << "can_use_conversion<D*&,D*&> = " << can_use_conversion<D*&,D*&>::value <<endl;
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cout << "can_use_conversion<D*,E*> = " << can_use_conversion<D*,E*>::value <<endl;
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cout << "can_use_dynamic_downcast<D*&,E*> = " << can_use_dynamic_downcast<D*&,E*>::value <<endl;
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cout << "can_use_conversion<E*,F*> = " << can_use_conversion<E*,F*>::value <<endl;
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cout << "can_use_dynamic_downcast<E*,F*> = " << can_use_dynamic_downcast<E*,F*>::value <<endl;
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cout << "=== standard case: References ==="<<endl;
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cout << "Access(D as D&) --->" << AccessCasted<D&>::access(d) <<endl;
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cout << "Access(D& as D&) --->" << AccessCasted<D&>::access(rD) <<endl;
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D dd1(d);
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// AccessCasted<D&>::access(move(dd1)); // does not compile since it would be dangerous; we can't take a l-value ref
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// AccessCasted<D&&>::access(rD); // from a r-value (move) reference and we can't move a l-value ref
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// AccessCasted<D&&>::access(d); //
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cout << "=== build a value object ==="<<endl;
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cout << "Access(D as D) --->" << AccessCasted<D>::access(d) <<endl;
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cout << "Access(D& as D) --->" << AccessCasted<D>::access(rD) <<endl;
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cout << "Access(D&& as D) --->" << AccessCasted<D>::access(move(dd1)) <<endl;
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cout << "=== take a pointer ==="<<endl;
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cout << "Access(D as D*) --->" << AccessCasted<D*>::access(d) <<endl;
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cout << "Access(D& as D*) --->" << AccessCasted<D*>::access(rD) <<endl;
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// AccessCasted<D*>::access(move(dd1)); // should not take value moved by r-value-ref as pointer, otherwise the moved object would be lost
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cout << "=== dereference a pointer ==="<<endl;
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cout << "Access(D* as D&) --->" << AccessCasted<D&>::access(pD) <<endl;
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cout << "Access(D* as D) --->" << AccessCasted<D>::access(pD) <<endl;
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D* pdd1(pD);
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cout << "Access(D*&& as D) --->" << AccessCasted<D>::access(move(pdd1)) <<endl;
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D* pNull(0);
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VERIFY_ERROR (BOTTOM_VALUE, AccessCasted<D>::access(pNull)); // run-time NULL check
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// AccessCasted<D&&>::access(pD); // should not move away a value accessed through a pointer, there might be other users
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cout << "=== const correctness ==="<<endl;
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cout << "Access(D as D const&) --->" << AccessCasted<D const&>::access(d) <<endl;
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cout << "Access(D& as D const&) --->" << AccessCasted<D const&>::access(rD) <<endl;
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cout << "Access(D as const D) --->" << AccessCasted<const D>::access(d) <<endl;
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cout << "Access(D& as const D) --->" << AccessCasted<const D>::access(rD) <<endl;
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cout << "Access(D as const D*) --->" << AccessCasted<const D*>::access(d) <<endl;
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cout << "Access(D& as const D*) --->" << AccessCasted<const D*>::access(rD) <<endl;
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cout << "Access(D* as D const&) --->" << AccessCasted<D const&>::access(pD) <<endl;
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cout << "Access(D* as const D) --->" << AccessCasted<const D>::access(pD) <<endl;
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const D cD(d);
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D const& rcD(d);
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const D* pcD(&cD);
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cout << "Access(const D as D const&) --->" << AccessCasted<D const&>::access(cD) <<endl;
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cout << "Access(D const& as D const&) --->" << AccessCasted<D const&>::access(rcD) <<endl;
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cout << "Access(const D as const D) --->" << AccessCasted<const D>::access(cD) <<endl;
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cout << "Access(D const& as const D) --->" << AccessCasted<const D>::access(rcD) <<endl;
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cout << "Access(const D as const D*) --->" << AccessCasted<const D*>::access(cD) <<endl;
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cout << "Access(D const& as const D*) --->" << AccessCasted<const D*>::access(rcD) <<endl;
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cout << "Access(const D* as D const&) --->" << AccessCasted<D const&>::access(pcD) <<endl;
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cout << "Access(const D* as const D) --->" << AccessCasted<const D>::access(pcD) <<endl;
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cout << "Access(D const& as D) --->" << AccessCasted<D>::access(rcD) <<endl; // it's OK to construct a new (non-const) object from const ref
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const D cD1(cD); // likewise it's OK to construct from move-ref. Actually, we're not
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cout << "Access(D const&& as D) --->" << AccessCasted<D>::access(move(cD1)) <<endl; // moving anything, but it's up to the receiving ctor to prevent that
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// AccessCasted<D&>::access(rcD); // normal ref from const ref is not const correct
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// AccessCasted<D*>::access(rcD); // likewise, regular pointer from const ref prohibited
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// AccessCasted<D&>::access(pcD); // likewise, regular ref from pointer-to-const
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// AccessCasted<D*>::access(pcD); // and regular pointer from pointer-to-const
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// AccessCasted<D&&>::access(rcD); // ruled out already because moving a reference is invalid
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// AccessCasted<D&&>::access(pcD); // ruled out already because moving a dereferenced pointer is invalid
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// AccessCasted<D&>::access(move(cD)); // ruled out already because taking reference from moved value is invalid
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// AccessCasted<D*>::access(move(cD)); // and same for taking pointer from a moved value.
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cout << "=== work cases: actual conversions ==="<<endl;
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cout << "Access(B& as B&) --->" << AccessCasted<B&>::access(rB) <<endl;
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cout << "Access(D& as B&) --->" << AccessCasted<B&>::access(rD) <<endl;
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cout << "Access(B* as B*) --->" << AccessCasted<B*>::access(pB) <<endl;
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cout << "Access(D* as B*) --->" << AccessCasted<B*>::access(pD) <<endl;
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cout << "Access(D& as B*) --->" << AccessCasted<B*>::access(rD) <<endl;
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cout << "Access(D* as B&) --->" << AccessCasted<B&>::access(pD) <<endl;
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cout << "Access(B*& as B*&) --->" << AccessCasted<B*&>::access(rpB) <<endl;
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cout << "Access(D*& as D*&) --->" << AccessCasted<D*&>::access(rpD) <<endl;
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cout << "Access(D& as const B*) --->" << AccessCasted<const B*>::access(rD) <<endl;
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cout << "Access(D* as B const&) --->" << AccessCasted<B const&>::access(pD) <<endl;
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cout << "Access(D const& as const B*) --->" << AccessCasted<const B*>::access(rcD) <<endl;
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cout << "Access(const D* as B const&) --->" << AccessCasted<B const&>::access(pcD) <<endl;
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// AccessCasted<B*&>::access(rpD); // ruled out, since it would allow to sneak-in a non-D object into the D*
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// AccessCasted<D&>::access(rB); // any down-casts are ruled out,
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// AccessCasted<D*>::access(pB); // since neither B nor D has RTTI
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// AccessCasted<D&>::access(pB); //
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// AccessCasted<D*>::access(rB); //
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// AccessCasted<E&>::access(rD); // we need RTTI on both ends to perform a safe dynamic downcast.
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// AccessCasted<D*>::access((B*)pD); // dangerous, since we have no way to know for sure it's indeed a D object
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// AccessCasted<E*>::access(pDE); // same here, since E has RTTI but D hasn't, we have no way to find out the real type
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VERIFY_ERROR (WRONG_TYPE, AccessCasted<F&>::access(rE)); // allowed by typing, but fails at runtime since it isn't an F-object
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cout << "Access(E(F)& as F&) --->" << AccessCasted<F&>::access(rEF) <<endl;
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cout << "Access(E(F)* as F*) --->" << AccessCasted<F*>::access(pEF) <<endl;
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cout << "Access(E(F)* as F&) --->" << AccessCasted<F&>::access(pEF) <<endl;
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cout << "Access(E(F)& as F*) --->" << AccessCasted<F*>::access(pEF) <<endl;
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cout << "Access(F* as X*) --->" << AccessCasted<X*>::access(pF) <<endl; // upcast to the other mixin is OK
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cout << "Access(X(F)* as X*) --->" << AccessCasted<X*>::access(pXF) <<endl; // (and note: address adjustment due to mixin layout)
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cout << "Access(F* as B&) --->" << AccessCasted<B&>::access(pF) <<endl; // upcast to base
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cout << "Access(F* as E&) --->" << AccessCasted<E&>::access(pF) <<endl; // upcast to parent (retaining the RTTI)
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// AccessCasted<X*>::access(pEF); // cross-cast not supported (to complicated to implement)
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// AccessCasted<F*>::access(pXF); // downcast not possible, since X does not provide RTTI
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int i = 2;
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float fp = 3.1415;
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cout << "Access(int as double) --->" << AccessCasted<double>::access(i) <<endl;
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cout << "Access(float as long) --->" << AccessCasted<long>::access(fp) <<endl;
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// AccessCasted<double&>::access(i); // would undermine the type system, thus ruled out
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// AccessCasted<double const&>::access(i); // allowed, but warning: returning reference to temporary (and the warning is justified)
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CHECK (isSameObject (d, AccessCasted<B&>::access(d)));
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CHECK (isSameObject (rD, AccessCasted<B&>::access(pD)));
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CHECK (isSameObject (d, AccessCasted<B const&>::access(pD)));
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CHECK (!isSameObject (d, AccessCasted<B>::access(rD)));
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CHECK (isSameObject (f, AccessCasted<F&>::access(rEF)));
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CHECK (!isSameObject (f, AccessCasted<X&>::access(pF))); // note: address adjustment due to layout of mixin object X
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}
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};
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/** Register this test class... */
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LAUNCHER (AccessCasted_test, "unit common");
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}} // namespace lib::meta::test
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