/**
 * @file `envAsBoolean` — coerce an env-var-shaped value into a boolean. Accepts
 *   a back-compat positional `defaultValue` or an options bag (with `trim`).
 *   Truthy vocabulary is `'1'` / `'true'` / `'yes'` case-insensitively after
 *   optional trim.
 */
import type { EnvAsBooleanOptions } from './types';
/**
 * Convert an environment variable value to a boolean.
 *
 * Back-compat overload: passing a bare boolean as the second argument is
 * equivalent to `{ defaultValue: B }`.
 *
 * @example
 *   ;```typescript
 *   import { envAsBoolean } from '@socketsecurity/lib/env/boolean'
 *
 *   envAsBoolean('true') // true
 *   envAsBoolean('1') // true
 *   envAsBoolean('yes') // true
 *   envAsBoolean('  true  ') // true (trimmed)
 *   envAsBoolean('  true  ', { trim: false }) // false (strict)
 *   envAsBoolean(undefined) // false
 *   envAsBoolean(undefined, true) // true (legacy positional default)
 *   ```
 *
 * @param value - The value to convert.
 * @param defaultValueOrOptions - Default (boolean) or options object.
 *
 * @returns `true` if value is '1', 'true', or 'yes' (case-insensitive), `false`
 *   otherwise.
 */
export declare function envAsBoolean(value: unknown, defaultValueOrOptions?: boolean | EnvAsBooleanOptions | undefined): boolean;
