Dune::detail::StructMPITraitsImpl< Struct, Members > Struct Template Reference

Generic MPI traits implementation for structs. More...

#include <ReservoirCouplingMpiTraits.hpp>

Static Public Member Functions
static MPI_Datatype	getType ()

Static Public Attributes
static constexpr bool	is_intrinsic = false

Detailed Description

template<class Struct, auto... Members>
struct Dune::detail::StructMPITraitsImpl< Struct, Members >

Generic MPI traits implementation for structs.

This class template provides automatic MPI datatype creation for C++ structs by analyzing the struct's member pointers. It generates an MPI_Datatype that correctly represents the memory layout of the struct, allowing it to be sent via MPI communication functions.

The implementation handles:

• Scalar fields of MPI-compatible types
• C-style arrays (T[N])
• std::array<T, N> containers
• Enum fields (using their underlying type)

Thread Safety: The MPI datatype is created exactly once using std::call_once() to ensure thread-safe initialization in case this code is called from multiple threads.

Usage Example:

struct MyData {
    double value;
    std::array<int, 3> counts;
};
 
// Define the trait by listing member pointers:
template<>
struct MPITraits<MyData>
    : detail::StructMPITraits<MyData, &MyData::value, &MyData::counts>
{ };
 
// Now MyData can be sent via MPI:
MPI_Send(&data, 1, MPITraits<MyData>::getType(), dest, tag, comm);

Template Parameters

Struct	The struct type for which to create an MPI datatype
Members	Variadic pack of pointers-to-members listing all fields to include

Assumptions: Each field of the struct must be either:

• An already defined MPI type (int, double, float, etc.)
• A C array or std::array of an already defined MPI type
• An enum whose underlying type is an already defined MPI type

Note

The order of member pointers in the template argument list determines the field order in the MPI datatype

The datatype is automatically resized to account for struct padding

See also

MPITraits

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The documentation for this struct was generated from the following file:

• opm/simulators/flow/rescoup/ReservoirCouplingMpiTraits.hpp