## nng_aio_set_input

Set input parameter.

### Synopsis

```c
#include <nng/nng.h>

void nng_aio_set_input(nng_aio *aio, unsigned int index, void *param);
```

### Description

The `nng_aio_set_input` function sets the input parameter at _index_
to _param_ for the asynchronous operation associated with _aio_.

The type and semantics of input parameters are determined by specific operations.
The caller must supply appropriate inputs for the operation to be performed.

The valid values of _index_ range from zero (0) to three (3), as no operation currently defined can accept more than four parameters.

NOTE: If the _index_ does not correspond to a defined input for the operation,
then this function will have no effect.

IMPORTANT: It is an error to call this function while the _aio_ is currently
in use by an active asynchronous operation.

An input parameter set with this function may be retrieved later with
the xref:../iop/nng_aio_get_input.adoc[`nng_aio_get_input`] function.

### See Also

xref:../iop/nng_aio_get_input.adoc[nng_aio_get_input],
xref:nng_aio_get_output.adoc[nng_aio_get_output],
xref:nng_aio_result.adoc[nng_aio_result]
