@stdlib/napi/create-int32/README.md

C APIs for creating Node-API native add-ons.

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# create_int32

> Convert a signed 32-bit integer to a Node-API value.

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## Usage

```javascript
var headerDir = require( '@stdlib/napi/create-int32' );
```

#### headerDir

Absolute file path for the directory containing header files for C APIs.

```javascript
var dir = headerDir;
// returns <string>
```

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## Examples

```javascript
var headerDir = require( '@stdlib/napi/create-int32' );

console.log( headerDir );
// => <string>
```

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* * *

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## C APIs

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### Usage

```c
#include "stdlib/napi/create_int32.h"
```

#### stdlib_napi_create_int32( env, value, \*out )

Converts a signed 32-bit integer to a Node-API value.

```c
#include "stdlib/napi/create_int32.h"
#include <node_api.h>

static napi_value addon( napi_env env, napi_callback_info info ) {
    
    // ...

    napi_value value;
    napi_status status = stdlib_napi_create_int32( env, 1, &value );
    assert( status == napi_ok );
    if ( err != NULL ) {
        assert( napi_throw( env, err ) == napi_ok );
        return NULL;
    }

    // ...
}
```

The function accepts the following arguments:

-   **env**: `[in] napi_env` environment under which the function is invoked.
-   **value**: `[in] int32_t` signed 32-bit integer.
-   **out**: `[out] napi_value*` destination for storing output value.

```c
napi_status stdlib_napi_create_int32( const napi_env env, const int32_t value, napi_value *out );
```

The function returns a `napi_status` status code indicating success or failure (returns `napi_ok` if success).

#### STDLIB_NAPI_CREATE_INT32( env, expression, name )

Macro for converting a signed 32-bit integer to a Node-API value.

```c
#include "stdlib/napi/create_int32.h"
#include "stdlib/napi/argv_int32.h"
#include "stdlib/napi/argv.h"
#include <node_api.h>
#include <stdint.h>

static int32_t fcn( const int32_t v ) {
    return v;
}

// ...

static napi_value addon( napi_env env, napi_callback_info info ) {
    // Retrieve add-on callback arguments:
    STDLIB_NAPI_ARGV( env, info, argv, argc, 1 );

    // Convert the first argument to a C type:
    STDLIB_NAPI_ARGV_INT32( env, value, argv, 0 );

    // ...

    // Convert a value having a C type to a Node-API value:
    STDLIB_NAPI_CREATE_INT32( env, fcn( value ), out );

    return out;
}
```

The macro expects the following arguments:

-   **env**: environment under which the callback is invoked.
-   **expression**: expression returning a signed 32-bit integer.
-   **name**: output variable name.

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