npm package: @stdlib/complex-base-cast-return
Description: Wrap a function and casts a function's return value to a complex number.
Author: The Stdlib Authors
Latest version: 0.2.3

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# castReturn

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> Wrap a function and cast a function's return value to a complex number.

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<section class="intro">

</section>

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<!-- Package usage documentation. -->

<section class="installation">

## Installation

```bash
npm install @stdlib/complex-base-cast-return
```

</section>

<section class="usage">

## Usage

```javascript
var castReturn = require( '@stdlib/complex-base-cast-return' );
```

#### castReturn( fcn, nargs, ctor )

Returns a function which wraps a function and casts a function's return value to a complex number.

```javascript
var Complex64 = require( '@stdlib/complex-float32-ctor' );
var addf = require( '@stdlib/number-float32-base-add' );

var f = castReturn( addf, 2, Complex64 );
// returns <Function>
```

The function accepts the following arguments:

-   **fcn**: the function to wrap.
-   **nargs**: the number of arguments to be provided to the wrapped function.
-   **ctor**: complex number constructor for converting real numbers to complex numbers.

</section>

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<!-- Package usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="notes">

## Notes

-   The returned function **assumes** that the wrapped function returns either a real or complex number.
-   The returned function **assumes** that, if a return value is non-numeric (i.e., not of type `number`), then the return value is a complex number. The returned function does **not** verify that non-numeric return values are, in fact, complex number objects. The returned function returns non-numeric return values from the wrapped function without modification.

</section>

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<!-- Package usage examples. -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var Complex64 = require( '@stdlib/complex-float32-ctor' );
var addf = require( '@stdlib/number-float32-base-add' );
var castReturn = require( '@stdlib/complex-base-cast-return' );

var f = castReturn( addf, 2, Complex64 );

// ...

var z = f( 3.0, 4.0 );
// returns <Complex64>[ 7.0, 0.0 ]

console.log( z.toString() );
// => '7 + 0i'
```

</section>

<!-- /.examples -->

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* * *

## Notice

This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].

#### Community

[![Chat][chat-image]][chat-url]

---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

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