import { CanActivate, ExecutionContext } from '@nestjs/common';
import { Reflector } from '@nestjs/core';
import type { FeatureFlagKey } from '@domain/types';
import { FeatureFlagService } from '@domain/featureFlags';
/**
 * Guard that ensures a feature flag is in the expected state
 * before allowing access to a route handler.
 *
 * @example
 * ```typescript
 * @Controller('premium')
 * @UseGuards(FeatureFlagGuard)
 * export class PremiumController {
 *   @Get()
 *   @FeatureEnabled('PREMIUM_FEATURE')
 *   getPremiumData() {
 *     // Only accessible if PREMIUM_FEATURE is enabled
 *   }
 * }
 * ```
 */
export declare class FeatureFlagGuard implements CanActivate {
    private readonly reflector;
    private readonly featureFlagService;
    private readonly logger;
    constructor(reflector: Reflector, featureFlagService: FeatureFlagService<FeatureFlagKey>);
    canActivate(context: ExecutionContext): Promise<boolean>;
    /**
     * Compare expected vs actual values.
     */
    private matches;
}
//# sourceMappingURL=feature-flag.guard.d.ts.map