npm package: @stdlib/ndarray-mostly-safe-casts
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.
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 ndarray [data types][@stdlib/ndarray/dtypes] to which a provided ndarray [data type][@stdlib/ndarray/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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<section class="installation">

## Installation

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

</section>

<section class="usage">

## Usage

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

#### mostlySafeCasts( \[dtype] )

If provided a `dtype` argument, returns a list of ndarray [data types][@stdlib/ndarray/dtypes] to which a provided ndarray [data type][@stdlib/ndarray/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="examples">

## Examples

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

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

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

// Print the list of ndarray 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/ndarray-casting-modes`][@stdlib/ndarray/casting-modes]</span><span class="delimiter">: </span><span class="description">list of ndarray casting modes.</span>
-   <span class="package-name">[`@stdlib/ndarray-dtypes`][@stdlib/ndarray/dtypes]</span><span class="delimiter">: </span><span class="description">list of ndarray data types.</span>
-   <span class="package-name">[`@stdlib/ndarray-safe-casts`][@stdlib/ndarray/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.</span>
-   <span class="package-name">[`@stdlib/ndarray-same-kind-casts`][@stdlib/ndarray/same-kind-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 or cast within the same kind.</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

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

---

## License

See [LICENSE][stdlib-license].


## Copyright

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

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