$values list of permissible enum values * @return string|null value of the environment variable, of null if not set or invalid * * @see https://opentelemetry.io/docs/specs/otel/configuration/sdk-environment-variables/#enum */ public function enum(string $name, array $values): ?string; /** * Resolves a boolean-valued environment variable. * * Allowed values: * - case-insensitive "true" * - case-insensitive "false" * * @param string $name environment variable name * @return bool|null value of the environment variable, or null if not set or invalid * * @see https://opentelemetry.io/docs/specs/otel/configuration/sdk-environment-variables/#boolean-value */ public function bool(string $name): ?bool; /** * Resolves an integer-valued environment variable. * * @param string $name environment variable name * @param int|null $min lower limit (inclusive), defaults to 0 * @param int|null $max upper limit (inclusive), defaults to 2^31-1 * @return int|null value of the environment variable, or null if not set or invalid * * @see https://opentelemetry.io/docs/specs/otel/configuration/sdk-environment-variables/#numeric-value */ public function int(string $name, ?int $min = 0, ?int $max = ~(-1 << 31)): int|null; /** * Resolves a numeric-valued environment variable. * * @param string $name environment variable name * @param int|float|null $min lower limit (inclusive), defaults to 0 * @param int|float|null $max upper limit (inclusive), defaults to 2^31-1 * @return int|float|null value of the environment variable, or null if not set or invalid * * @see https://opentelemetry.io/docs/specs/otel/configuration/sdk-environment-variables/#numeric-value */ public function numeric(string $name, int|float|null $min = 0, int|float|null $max = ~(-1 << 31)): float|int|null; /** * Resolves a list-valued environment variable. * * @param string $name environment variable name * @return list|null value of the environment variable, or null if not set or invalid */ public function list(string $name): ?array; /** * Resolves a map-valued environment variable. * * @param string $name environment variable name * @return array|null value of the environment variable, or null if not set or invalid */ public function map(string $name): ?array; }