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value_init doc + test: Merged from trunk changeset [42798] to release.

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[SVN r42799]
This commit is contained in:
Niels Dekker
2008-01-15 19:55:28 +00:00
parent 88099a882f
commit 97b8966337
2 changed files with 310 additions and 28 deletions
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173
value_init_test.cpp
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@@ -1,4 +1,4 @@
// Copyright 2002, Fernando Luis Cacciola Carballal.
// Copyright 2002-2008, Fernando Luis Cacciola Carballal.
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
@@ -6,12 +6,15 @@
//
// Test program for "boost/utility/value_init.hpp"
//
// Initial: 21 Agu 2002
// 21 Agu 2002 (Created) Fernando Cacciola
// 15 Jan 2008 (Added tests regarding compiler issues) Fernando Cacciola, Niels Dekker
#include <cstring> // For memcmp.
#include <iostream>
#include <string>
#include "boost/utility/value_init.hpp"
#include <boost/shared_ptr.hpp>
#ifdef __BORLANDC__
#pragma hdrstop
@@ -62,6 +65,9 @@ struct NonPOD : NonPODBase
//
// Sample aggregate POD struct type
// Some compilers do not correctly value-initialize such a struct, for example:
// Borland C++ Report #51854, "Value-initialization: POD struct should be zero-initialized "
// http://qc.codegear.com/wc/qcmain.aspx?d=51854
//
struct AggregatePODStruct
{
@@ -73,6 +79,106 @@ struct AggregatePODStruct
bool operator == ( AggregatePODStruct const& lhs, AggregatePODStruct const& rhs )
{ return lhs.f == rhs.f && lhs.c == rhs.c && lhs.i == rhs.i ; }
//
// An aggregate struct that contains an std::string and an int.
// Pavel Kuznetsov (MetaCommunications Engineering) used a struct like
// this to reproduce the Microsoft Visual C++ compiler bug, reported as
// Feedback ID 100744, "Value-initialization in new-expression"
// https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=100744
//
struct StringAndInt
{
std::string s;
int i;
};
bool operator == ( StringAndInt const& lhs, StringAndInt const& rhs )
{ return lhs.s == rhs.s && lhs.i == rhs.i ; }
//
// A struct that has an explicit (user defined) destructor.
// Some compilers do not correctly value-initialize such a struct, for example:
// Microsoft Visual C++, Feedback ID 100744, "Value-initialization in new-expression"
// https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=100744
//
struct StructWithDestructor
{
int i;
~StructWithDestructor() {}
};
bool operator == ( StructWithDestructor const& lhs, StructWithDestructor const& rhs )
{ return lhs.i == rhs.i ; }
//
// A struct that has a virtual function.
// Some compilers do not correctly value-initialize such a struct either, for example:
// Microsoft Visual C++, Feedback ID 100744, "Value-initialization in new-expression"
// https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=100744
//
struct StructWithVirtualFunction
{
int i;
virtual void VirtualFunction();
};
void StructWithVirtualFunction::VirtualFunction()
{
}
bool operator == ( StructWithVirtualFunction const& lhs, StructWithVirtualFunction const& rhs )
{ return lhs.i == rhs.i ; }
//
// A struct that is derived from an aggregate POD struct.
// Some compilers do not correctly value-initialize such a struct, for example:
// GCC Bugzilla Bug 30111, "Value-initialization of POD base class doesn't initialize members",
// reported by Jonathan Wakely, http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30111
//
struct DerivedFromAggregatePODStruct : AggregatePODStruct
{
DerivedFromAggregatePODStruct() : AggregatePODStruct() {}
};
//
// A struct that wraps an aggregate POD struct as data member.
//
struct AggregatePODStructWrapper
{
AggregatePODStructWrapper() : dataMember() {}
AggregatePODStruct dataMember;
};
bool operator == ( AggregatePODStructWrapper const& lhs, AggregatePODStructWrapper const& rhs )
{ return lhs.dataMember == rhs.dataMember ; }
typedef unsigned char ArrayOfBytes[256];
//
// A struct that allows testing whether the appropriate copy functions are called.
//
struct CopyFunctionCallTester
{
bool is_copy_constructed;
bool is_assignment_called;
CopyFunctionCallTester()
: is_copy_constructed(false), is_assignment_called(false) {}
CopyFunctionCallTester(const CopyFunctionCallTester & )
: is_copy_constructed(true), is_assignment_called(false) {}
CopyFunctionCallTester & operator=(const CopyFunctionCallTester & )
{
is_assignment_called = true ;
return *this ;
}
};
//
// This test function tests boost::value_initialized<T> for a specific type T.
@@ -97,6 +203,16 @@ bool test ( T const& y, T const& z )
x_c_ref = z ;
BOOST_CHECK ( x_c == z ) ;
boost::value_initialized<T> const copy1 = x;
BOOST_CHECK ( boost::get(copy1) == boost::get(x) ) ;
boost::value_initialized<T> copy2;
copy2 = x;
BOOST_CHECK ( boost::get(copy2) == boost::get(x) ) ;
boost::shared_ptr<boost::value_initialized<T> > ptr( new boost::value_initialized<T> );
BOOST_CHECK ( y == *ptr ) ;
#if !BOOST_WORKAROUND(BOOST_MSVC, < 1300)
boost::value_initialized<T const> cx ;
BOOST_CHECK ( y == cx ) ;
@@ -106,6 +222,7 @@ bool test ( T const& y, T const& z )
BOOST_CHECK ( y == cx_c ) ;
BOOST_CHECK ( y == boost::get(cx_c) ) ;
#endif
return boost::minimal_test::errors_counter() == counter_before_test ;
}
@@ -123,13 +240,57 @@ int test_main(int, char **)
AggregatePODStruct nonZeroInitializedAggregatePODStruct = { 1.25f, 'a', -1 };
BOOST_CHECK ( test(zeroInitializedAggregatePODStruct, nonZeroInitializedAggregatePODStruct) );
StringAndInt stringAndInt0;
StringAndInt stringAndInt1;
stringAndInt0.i = 0;
stringAndInt1.i = 1;
stringAndInt1.s = std::string("1");
BOOST_CHECK ( test(stringAndInt0, stringAndInt1) );
StructWithDestructor structWithDestructor0;
StructWithDestructor structWithDestructor1;
structWithDestructor0.i = 0;
structWithDestructor1.i = 1;
BOOST_CHECK ( test(structWithDestructor0, structWithDestructor1) );
StructWithVirtualFunction structWithVirtualFunction0;
StructWithVirtualFunction structWithVirtualFunction1;
structWithVirtualFunction0.i = 0;
structWithVirtualFunction1.i = 1;
BOOST_CHECK ( test(structWithVirtualFunction0, structWithVirtualFunction1) );
DerivedFromAggregatePODStruct derivedFromAggregatePODStruct0;
DerivedFromAggregatePODStruct derivedFromAggregatePODStruct1;
static_cast<AggregatePODStruct &>(derivedFromAggregatePODStruct0) = zeroInitializedAggregatePODStruct;
static_cast<AggregatePODStruct &>(derivedFromAggregatePODStruct1) = nonZeroInitializedAggregatePODStruct;
BOOST_CHECK ( test(derivedFromAggregatePODStruct0, derivedFromAggregatePODStruct1) );
AggregatePODStructWrapper aggregatePODStructWrapper0;
AggregatePODStructWrapper aggregatePODStructWrapper1;
aggregatePODStructWrapper0.dataMember = zeroInitializedAggregatePODStruct;
aggregatePODStructWrapper1.dataMember = nonZeroInitializedAggregatePODStruct;
BOOST_CHECK ( test(aggregatePODStructWrapper0, aggregatePODStructWrapper1) );
ArrayOfBytes zeroInitializedArrayOfBytes = { 0 };
boost::value_initialized<ArrayOfBytes> valueInitializedArrayOfBytes;
BOOST_CHECK (std::memcmp(get(valueInitializedArrayOfBytes), zeroInitializedArrayOfBytes, sizeof(ArrayOfBytes)) == 0);
boost::value_initialized<CopyFunctionCallTester> copyFunctionCallTester1;
BOOST_CHECK ( ! get(copyFunctionCallTester1).is_copy_constructed);
BOOST_CHECK ( ! get(copyFunctionCallTester1).is_assignment_called);
boost::value_initialized<CopyFunctionCallTester> copyFunctionCallTester2 = boost::value_initialized<CopyFunctionCallTester>(copyFunctionCallTester1);
BOOST_CHECK ( get(copyFunctionCallTester2).is_copy_constructed);
BOOST_CHECK ( ! get(copyFunctionCallTester2).is_assignment_called);
boost::value_initialized<CopyFunctionCallTester> copyFunctionCallTester3;
copyFunctionCallTester3 = boost::value_initialized<CopyFunctionCallTester>(copyFunctionCallTester1);
BOOST_CHECK ( ! get(copyFunctionCallTester3).is_copy_constructed);
BOOST_CHECK ( get(copyFunctionCallTester3).is_assignment_called);
return 0;
}
unsigned int expected_failures = 0;