ENH: add stdFoam::span container
- basic functionality similar to std::span (C++20). Holds pointer and size: for lightweight handling of address ranges. - implements cdata_bytes() and data_bytes() methods for similarity with UList. For span, however, both container accesses are const but the data_bytes() method is only available when the underlying pointer is non-const. No specializations of std::as_bytes() or std::as_writeable_bytes() as free functions, since std::byte etc are not available anyhow.
This commit is contained in:
Mark Olesen
parent
375a4792f9
commit
702225c249
3
applications/test/span/Make/files
Normal file
3
applications/test/span/Make/files
Normal file
@ -0,0 +1,3 @@
|
||||
Test-stdFoam-span.C
|
||||
|
||||
EXE = $(FOAM_USER_APPBIN)/Test-stdFoam-span
|
||||
2
applications/test/span/Make/options
Normal file
2
applications/test/span/Make/options
Normal file
@ -0,0 +1,2 @@
|
||||
/* EXE_INC = */
|
||||
/* EXE_LIBS = */
|
||||
156
applications/test/span/Test-stdFoam-span.C
Normal file
156
applications/test/span/Test-stdFoam-span.C
Normal file
@ -0,0 +1,156 @@
|
||||
/*---------------------------------------------------------------------------*\
|
||||
========= |
|
||||
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
|
||||
\\ / O peration |
|
||||
\\ / A nd | www.openfoam.com
|
||||
\\/ M anipulation |
|
||||
-------------------------------------------------------------------------------
|
||||
Copyright (C) 2023 OpenCFD Ltd.
|
||||
-------------------------------------------------------------------------------
|
||||
License
|
||||
This file is part of OpenFOAM.
|
||||
|
||||
OpenFOAM is free software: you can redistribute it and/or modify it
|
||||
under the terms of the GNU General Public License as published by
|
||||
the Free Software Foundation, either version 3 of the License, or
|
||||
(at your option) any later version.
|
||||
|
||||
OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
|
||||
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
||||
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
||||
for more details.
|
||||
|
||||
You should have received a copy of the GNU General Public License
|
||||
along with OpenFOAM. If not, see <http://www.gnu.org/licenses/>.
|
||||
|
||||
Application
|
||||
Test-stdFoam-span
|
||||
|
||||
Description
|
||||
Basic functionality test for span
|
||||
|
||||
\*---------------------------------------------------------------------------*/
|
||||
|
||||
#include "argList.H"
|
||||
|
||||
#include "IOstreams.H"
|
||||
#include "StringStream.H"
|
||||
#include "scalar.H"
|
||||
#include "vector.H"
|
||||
#include "labelRange.H"
|
||||
#include "scalarList.H"
|
||||
|
||||
using namespace Foam;
|
||||
|
||||
template<class Type>
|
||||
void printInfo(const UList<Type>& list)
|
||||
{
|
||||
Info<< "list: " << flatOutput(list) << nl
|
||||
<< "data: " << Foam::name(list.cdata())
|
||||
<< " size: " << Foam::name(list.size()) << nl;
|
||||
}
|
||||
|
||||
|
||||
template<class Type>
|
||||
void printInfo(const stdFoam::span<Type> span)
|
||||
{
|
||||
Info<< "span: " << Foam::name(span.data())
|
||||
<< ", " << span.size() << nl;
|
||||
}
|
||||
|
||||
template<class Type>
|
||||
void printContent(const stdFoam::span<Type> span)
|
||||
{
|
||||
Info<< "range:";
|
||||
for (const auto& val : span)
|
||||
{
|
||||
Info<< " " << val;
|
||||
}
|
||||
Info<< nl;
|
||||
}
|
||||
|
||||
|
||||
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
|
||||
// Main program:
|
||||
|
||||
int main(int argc, char *argv[])
|
||||
{
|
||||
argList::noParallel();
|
||||
argList::noFunctionObjects();
|
||||
|
||||
#include "setRootCase.H"
|
||||
|
||||
{
|
||||
const List<label> list1(identity(15));
|
||||
|
||||
printInfo(list1);
|
||||
|
||||
stdFoam::span<const label> span1;
|
||||
printInfo(span1);
|
||||
|
||||
span1 = stdFoam::span<const label>(list1.cdata(), list1.size());
|
||||
printInfo(span1);
|
||||
printContent(span1);
|
||||
|
||||
auto subspan1 = span1.subspan(5);
|
||||
|
||||
printInfo(subspan1);
|
||||
printContent(subspan1);
|
||||
|
||||
subspan1 = span1.subspan(5, 30);
|
||||
printInfo(subspan1);
|
||||
printContent(subspan1);
|
||||
|
||||
// non-const access: span1[6] = -100;
|
||||
// non-const access: Info<< Foam::name(span1.data_bytes()) << endl;
|
||||
|
||||
Info<< Foam::name(span1.cdata_bytes()) << endl;
|
||||
}
|
||||
|
||||
{
|
||||
List<label> list1(identity(15));
|
||||
|
||||
printInfo(list1);
|
||||
|
||||
stdFoam::span<label> span1;
|
||||
printInfo(span1);
|
||||
|
||||
span1 = stdFoam::span<label>(list1.data(), list1.size());
|
||||
printInfo(span1);
|
||||
printContent(span1);
|
||||
|
||||
auto subspan1 = span1.subspan(5);
|
||||
|
||||
printInfo(subspan1);
|
||||
printContent(subspan1);
|
||||
|
||||
subspan1 = span1.subspan(5, 30);
|
||||
printInfo(subspan1);
|
||||
printContent(subspan1);
|
||||
|
||||
span1[6] = -100;
|
||||
printInfo(span1);
|
||||
printContent(span1);
|
||||
|
||||
Info<< Foam::name(span1.data_bytes()) << endl;
|
||||
|
||||
|
||||
// With const span
|
||||
const auto span2 = stdFoam::span<label>(list1.data(), list1.size());
|
||||
printContent(span2);
|
||||
|
||||
// Span may be const, but its contents (pointers) needn't be
|
||||
span2[1] = 100;
|
||||
span2.front() = -1000;
|
||||
span2.back() = 1000;
|
||||
printInfo(list1);
|
||||
|
||||
printContent(span2.first(5));
|
||||
printContent(span2.last(5));
|
||||
}
|
||||
|
||||
Info<< "\nDone\n" << nl;
|
||||
return 0;
|
||||
}
|
||||
|
||||
// ************************************************************************* //
|
||||
@ -5,7 +5,7 @@
|
||||
\\ / A nd | www.openfoam.com
|
||||
\\/ M anipulation |
|
||||
-------------------------------------------------------------------------------
|
||||
Copyright (C) 2017-2022 OpenCFD Ltd.
|
||||
Copyright (C) 2017-2023 OpenCFD Ltd.
|
||||
-------------------------------------------------------------------------------
|
||||
License
|
||||
This file is part of OpenFOAM.
|
||||
@ -36,6 +36,7 @@ Description
|
||||
#include <initializer_list>
|
||||
#include <memory>
|
||||
#include <utility>
|
||||
#include <type_traits>
|
||||
|
||||
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
|
||||
|
||||
@ -397,6 +398,176 @@ constexpr inline const T& max(const T& a, const T& b)
|
||||
)
|
||||
|
||||
|
||||
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
|
||||
|
||||
namespace stdFoam
|
||||
{
|
||||
|
||||
/*---------------------------------------------------------------------------*\
|
||||
Class stdFoam::span Declaration
|
||||
\*---------------------------------------------------------------------------*/
|
||||
|
||||
//- Rudimentary functionality similar to std::span for holding memory view
|
||||
template<class Type>
|
||||
class span
|
||||
{
|
||||
// Private Data
|
||||
|
||||
//- The data pointer
|
||||
Type* data_;
|
||||
|
||||
//- The size of the span
|
||||
std::size_t size_;
|
||||
|
||||
|
||||
public:
|
||||
|
||||
// STL type definitions
|
||||
|
||||
using element_type = Type;
|
||||
using value_type = std::remove_cv<Type>;
|
||||
using size_type = std::size_t;
|
||||
using pointer = Type*;
|
||||
using const_pointer = const Type*;
|
||||
using reference = Type&;
|
||||
using const_reference = const Type&;
|
||||
using difference_type = std::ptrdiff_t;
|
||||
using iterator = Type*;
|
||||
|
||||
|
||||
// Generated Methods
|
||||
|
||||
//- Copy construct
|
||||
span(const span& other) noexcept = default;
|
||||
|
||||
//- Copy assignment
|
||||
span& operator=(const span& other) noexcept = default;
|
||||
|
||||
|
||||
// Constructors
|
||||
|
||||
//- Default construct
|
||||
constexpr span() noexcept
|
||||
:
|
||||
data_(nullptr),
|
||||
size_(0)
|
||||
{}
|
||||
|
||||
//- Construct from pointer and size
|
||||
constexpr span(pointer ptr, size_type count) noexcept
|
||||
:
|
||||
data_(ptr),
|
||||
size_(count)
|
||||
{}
|
||||
|
||||
//- Construct from begin/end pointers
|
||||
constexpr span(pointer first, pointer last) noexcept
|
||||
:
|
||||
data_(first),
|
||||
size_(last - first)
|
||||
{}
|
||||
|
||||
|
||||
//- Destructor
|
||||
~span() noexcept = default;
|
||||
|
||||
|
||||
// Member Functions
|
||||
|
||||
// Iterators
|
||||
|
||||
//- Iterator to begin of span
|
||||
constexpr iterator begin() const noexcept { return data_; }
|
||||
|
||||
//- Iterator to one-past end of span
|
||||
constexpr iterator end() const noexcept { return (data_ + size_); }
|
||||
|
||||
|
||||
// Element access
|
||||
|
||||
//- Access the first element. Undefined if span is empty
|
||||
constexpr reference front() const { return *(data_); }
|
||||
|
||||
//- Access the last element. Undefined if span is empty
|
||||
constexpr reference back() const { return *(data_ + size_ - 1); }
|
||||
|
||||
//- Access an element of the sequence
|
||||
constexpr reference operator[](size_type idx) const
|
||||
{
|
||||
return *(data_ + idx);
|
||||
}
|
||||
|
||||
//- Return a pointer to the beginning of the sequence
|
||||
constexpr pointer data() const noexcept { return data_; }
|
||||
|
||||
|
||||
// Observers
|
||||
|
||||
//- Number of elements in the sequence
|
||||
constexpr size_type size() const noexcept { return size_; }
|
||||
|
||||
//- The size of the sequence in bytes
|
||||
constexpr size_type size_bytes() const noexcept
|
||||
{
|
||||
return (size_*sizeof(Type));
|
||||
}
|
||||
|
||||
//- True if the sequence is empty
|
||||
constexpr bool empty() const noexcept { return !size_; }
|
||||
|
||||
|
||||
// Subview
|
||||
|
||||
//- Obtains a span of the first count elements
|
||||
span<Type> first(size_type count) const noexcept
|
||||
{
|
||||
return span<Type>(data_, count);
|
||||
}
|
||||
|
||||
//- Obtains a span of the last count elements
|
||||
span<Type> last(size_type count) const noexcept
|
||||
{
|
||||
return span<Type>(data_ + (size_ - count), count);
|
||||
}
|
||||
|
||||
//- Obtains a sub-span starting at pos until end of the sequence
|
||||
span<Type> subspan(size_type pos) const noexcept
|
||||
{
|
||||
return span<Type>(data_ + pos, size_ - pos);
|
||||
}
|
||||
|
||||
//- Obtains a sub-span of length len starting at pos.
|
||||
// Graciously handles excess lengths.
|
||||
span<Type> subspan(size_type pos, size_type len) const noexcept
|
||||
{
|
||||
return span<Type>(data_ + pos, std::min(size_ - pos, len));
|
||||
}
|
||||
|
||||
|
||||
// Additional members, similar to UList etc.
|
||||
// The std::span has as_bytes() and as_writeable_bytes() as free functions
|
||||
|
||||
//- A readonly view as byte content
|
||||
constexpr const char* cdata_bytes() const noexcept
|
||||
{
|
||||
return reinterpret_cast<const char*>(data_);
|
||||
}
|
||||
|
||||
//- A writable view as byte content (if the pointer type is non-const).
|
||||
//- Like data(), the const access itself is const.
|
||||
template<class TypeT = Type>
|
||||
typename std::enable_if<!std::is_const<TypeT>::value, char*>::type
|
||||
data_bytes() const noexcept
|
||||
{
|
||||
return reinterpret_cast<char*>(data_);
|
||||
}
|
||||
};
|
||||
|
||||
|
||||
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
|
||||
|
||||
} // End namespace stdFoam
|
||||
|
||||
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
|
||||
|
||||
#endif
|
||||
|
||||
Loading…
Reference in New Issue
Block a user