npm package: @stdlib/array-mostly-safe-casts
Description: Return a list of array data types to which a provided array data type can be safely cast and, for floating-point data types, can be downcast.
Author: The Stdlib Authors
Latest version: 0.4.1

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# Mostly Safe Casts

[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] <!-- [![dependencies][dependencies-image]][dependencies-url] -->

> Return a list of array [data types][@stdlib/array/dtypes] to which a provided array [data type][@stdlib/array/dtypes] can be safely cast and, for floating-point data types, can be downcast.

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<section class="intro">

</section>

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<!-- Package usage documentation. -->

<section class="installation">

## Installation

```bash
npm install @stdlib/array-mostly-safe-casts
```

</section>

<section class="usage">

## Usage

```javascript
var mostlySafeCasts = require( '@stdlib/array-mostly-safe-casts' );
```

#### mostlySafeCasts( \[dtype] )

If provided a `dtype` argument, returns a list of array [data types][@stdlib/array/dtypes] to which a provided array [data type][@stdlib/array/dtypes] can be safely cast and, for floating-point data types, can be downcast.

```javascript
var out = mostlySafeCasts( 'float32' );
// e.g., returns [ 'float32', 'float64', ... ]
```

If not provided a `dtype` argument, the function returns a casting table.

```javascript
var out = mostlySafeCasts();
// returns {...}

var f32 = out[ 'float32' ];
// returns {...}

var v = f32[ 'float64' ];
// returns 1
```

If provided an unrecognized or unsupported `dtype`, the function returns `null`.

```javascript
var out = mostlySafeCasts( 'foo' );
// returns null
```

</section>

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<section class="notes">

</section>

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<section class="examples">

## Examples

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

```javascript
var dtypes = require( '@stdlib/array-dtypes' );
var mostlySafeCasts = require( '@stdlib/array-mostly-safe-casts' );

// Get the list of supported array data types:
var DTYPES = dtypes();

// Print the list of array data types to which a data type can be cast...
var list;
var i;
for ( i = 0; i < DTYPES.length; i++ ) {
    list = mostlySafeCasts( DTYPES[ i ] );
    console.log( '%s: %s', DTYPES[ i ], list.join( ', ' ) );
}
```

</section>

<!-- /.examples -->

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</section>

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<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/array-convert`][@stdlib/array/convert]</span><span class="delimiter">: </span><span class="description">convert an array to an array of a different data type.</span>
-   <span class="package-name">[`@stdlib/array-convert-same`][@stdlib/array/convert-same]</span><span class="delimiter">: </span><span class="description">convert an array to the same data type as a second input array.</span>
-   <span class="package-name">[`@stdlib/array-dtypes`][@stdlib/array/dtypes]</span><span class="delimiter">: </span><span class="description">list of array data types.</span>
-   <span class="package-name">[`@stdlib/array-safe-casts`][@stdlib/array/safe-casts]</span><span class="delimiter">: </span><span class="description">return a list of array data types to which a provided array data type can be safely cast.</span>
-   <span class="package-name">[`@stdlib/array-same-kind-casts`][@stdlib/array/same-kind-casts]</span><span class="delimiter">: </span><span class="description">return a list of array data types to which a provided array data type can be safely cast or cast within the same kind.</span>
-   <span class="package-name">[`@stdlib/ndarray-mostly-safe-casts`][@stdlib/ndarray/mostly-safe-casts]</span><span class="delimiter">: </span><span class="description">return a list of ndarray data types to which a provided ndarray data type can be safely cast and, for floating-point data types, can be downcast.</span>

</section>

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<section class="main-repo" >

* * *

## 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

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---

## License

See [LICENSE][stdlib-license].


## Copyright

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

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