npm package: @stdlib/ndarray-base-assert-is-allowed-data-type-cast
Description: Determine if an ndarray data type can be cast to another ndarray data type according to a specified casting mode.
Author: The Stdlib Authors
Latest version: 0.3.1

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# isAllowedCast

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> Determine whether an ndarray [data type][@stdlib/ndarray/dtypes] can be cast to another ndarray [data type][@stdlib/ndarray/dtypes] according to a specified [casting mode][@stdlib/ndarray/casting-modes].

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<section class="installation">

## Installation

```bash
npm install @stdlib/ndarray-base-assert-is-allowed-data-type-cast
```

</section>

<section class="usage">

## Usage

```javascript
var isAllowedCast = require( '@stdlib/ndarray-base-assert-is-allowed-data-type-cast' );
```

#### isAllowedCast( from, to, casting )

Returns a boolean indicating whether an ndarray [data type][@stdlib/ndarray/dtypes] can be cast to another ndarray [data type][@stdlib/ndarray/dtypes] according to a specified [casting][@stdlib/ndarray/casting-modes] mode.

```javascript
var bool = isAllowedCast( 'float32', 'float64', 'safe' );
// returns true

bool = isAllowedCast( 'float64', 'int32', 'safe' );
// returns false
```

The following [casting][@stdlib/ndarray/casting-modes] modes are supported:

-   **none**: only allow casting between identical types.
-   **equiv**: allow casting between identical and byte swapped types.
-   **safe**: only allow "safe" casts.
-   **mostly-safe**: allow "safe" casts and, for floating-point data types, downcasts.
-   **same-kind**: allow "safe" casts and casts within the same kind (e.g., between signed integers or between floats).
-   **unsafe**: allow casting between all types (including between integers and floats).

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<section class="examples">

## Examples

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

```javascript
var nCartesianProduct = require( '@stdlib/array-base-n-cartesian-product' );
var unzip = require( '@stdlib/utils-unzip' );
var dtypes = require( '@stdlib/ndarray-base-dtype-strings' );
var modes = require( '@stdlib/ndarray-casting-modes' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var isAllowedCast = require( '@stdlib/ndarray-base-assert-is-allowed-data-type-cast' );

// Generate a list of dtype pairs and casting modes:
var pairs = nCartesianProduct( dtypes(), dtypes(), modes() );

// Unzip the list into individual arrays:
var lists = unzip( pairs );

// For each data type pair and mode, determine whether one can cast to another data type:
logEachMap( '%s => %s. %s: %s.', lists[ 0 ], lists[ 1 ], lists[ 2 ], isAllowedCast );
```

</section>

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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].

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---

## License

See [LICENSE][stdlib-license].


## Copyright

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

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