.. _man3-PMIx_Topology_construct: PMIx_Topology_construct ======================= .. include_body ``PMIx_Topology_construct`` |mdash| Initialize a caller-provided :ref:`pmix_topology_t(5) ` structure. SYNOPSIS -------- .. code-block:: c #include void PMIx_Topology_construct(pmix_topology_t *t); Python Syntax ^^^^^^^^^^^^^ No Python equivalent INPUT PARAMETERS ---------------- * ``t``: Pointer to the :ref:`pmix_topology_t(5) ` structure to be initialized. The storage for the structure itself must already exist |mdash| it is supplied by the caller (typically declared on the stack or embedded within another object). DESCRIPTION ----------- Initialize the memory of a :ref:`pmix_topology_t ` that the caller has already allocated. The function zeroes the entire structure, clearing the ``source`` string pointer and the ``topology`` pointer. No heap memory is allocated and no topology object is attached; the caller is responsible for populating the fields after construction. RETURN VALUE ------------ ``PMIx_Topology_construct`` returns no value (``void``). NOTES ----- Because ``PMIx_Topology_construct`` operates on caller-provided storage, it must be paired with :ref:`PMIx_Topology_destruct(3) ` to release any payload the structure subsequently acquires. Do **not** pass a constructed (as opposed to created) structure to :ref:`PMIx_Topology_free(3) `, as that would attempt to free storage the library did not allocate. An equivalent static initializer, ``PMIX_TOPOLOGY_STATIC_INIT``, is available for initializing a structure at the point of declaration. EXAMPLES -------- Construct a structure: .. code-block:: c pmix_topology_t topo; PMIx_Topology_construct(&topo); .. seealso:: :ref:`PMIx_Topology_destruct(3) `, :ref:`PMIx_Topology_create(3) `, :ref:`PMIx_Topology_free(3) `, :ref:`pmix_topology_t(5) `