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//! Structured values.
use std::fmt;
extern crate value_bag;
#[cfg(feature = "kv_unstable_sval")]
extern crate sval;
#[cfg(feature = "kv_unstable_sval")]
extern crate sval_ref;
#[cfg(feature = "kv_unstable_serde")]
extern crate serde;
use self::value_bag::ValueBag;
pub use kv::Error;
/// A type that can be converted into a [`Value`](struct.Value.html).
pub trait ToValue {
/// Perform the conversion.
fn to_value(&self) -> Value;
}
impl<'a, T> ToValue for &'a T
where
T: ToValue + ?Sized,
{
fn to_value(&self) -> Value {
(**self).to_value()
}
}
impl<'v> ToValue for Value<'v> {
fn to_value(&self) -> Value {
Value {
inner: self.inner.clone(),
}
}
}
/// Get a value from a type implementing `std::fmt::Debug`.
#[macro_export]
macro_rules! as_debug {
($capture:expr) => {
$crate::kv::Value::from_debug(&$capture)
};
}
/// Get a value from a type implementing `std::fmt::Display`.
#[macro_export]
macro_rules! as_display {
($capture:expr) => {
$crate::kv::Value::from_display(&$capture)
};
}
/// Get a value from an error.
#[cfg(feature = "kv_unstable_std")]
#[macro_export]
macro_rules! as_error {
($capture:expr) => {
$crate::kv::Value::from_dyn_error(&$capture)
};
}
#[cfg(feature = "kv_unstable_serde")]
/// Get a value from a type implementing `serde::Serialize`.
#[macro_export]
macro_rules! as_serde {
($capture:expr) => {
$crate::kv::Value::from_serde(&$capture)
};
}
/// Get a value from a type implementing `sval::Value`.
#[cfg(feature = "kv_unstable_sval")]
#[macro_export]
macro_rules! as_sval {
($capture:expr) => {
$crate::kv::Value::from_sval(&$capture)
};
}
/// A value in a structured key-value pair.
///
/// # Capturing values
///
/// There are a few ways to capture a value:
///
/// - Using the `Value::capture_*` methods.
/// - Using the `Value::from_*` methods.
/// - Using the `ToValue` trait.
/// - Using the standard `From` trait.
///
/// ## Using the `Value::capture_*` methods
///
/// `Value` offers a few constructor methods that capture values of different kinds.
/// These methods require a `T: 'static` to support downcasting.
///
/// ```
/// use log::kv::Value;
///
/// let value = Value::capture_debug(&42i32);
///
/// assert_eq!(Some(42), value.to_i64());
/// ```
///
/// ## Using the `Value::from_*` methods
///
/// `Value` offers a few constructor methods that capture values of different kinds.
/// These methods don't require `T: 'static`, but can't support downcasting.
///
/// ```
/// use log::kv::Value;
///
/// let value = Value::from_debug(&42i32);
///
/// assert_eq!(None, value.to_i64());
/// ```
///
/// ## Using the `ToValue` trait
///
/// The `ToValue` trait can be used to capture values generically.
/// It's the bound used by `Source`.
///
/// ```
/// # use log::kv::ToValue;
/// let value = 42i32.to_value();
///
/// assert_eq!(Some(42), value.to_i64());
/// ```
///
/// ```
/// # use std::fmt::Debug;
/// use log::kv::ToValue;
///
/// let value = (&42i32 as &dyn Debug).to_value();
///
/// assert_eq!(None, value.to_i64());
/// ```
///
/// ## Using the standard `From` trait
///
/// Standard types that implement `ToValue` also implement `From`.
///
/// ```
/// use log::kv::Value;
///
/// let value = Value::from(42i32);
///
/// assert_eq!(Some(42), value.to_i64());
/// ```
pub struct Value<'v> {
inner: ValueBag<'v>,
}
impl<'v> Value<'v> {
/// Get a value from a type implementing `ToValue`.
pub fn from_any<T>(value: &'v T) -> Self
where
T: ToValue,
{
value.to_value()
}
/// Get a value from a type implementing `std::fmt::Debug`.
pub fn capture_debug<T>(value: &'v T) -> Self
where
T: fmt::Debug + 'static,
{
Value {
inner: ValueBag::capture_debug(value),
}
}
/// Get a value from a type implementing `std::fmt::Display`.
pub fn capture_display<T>(value: &'v T) -> Self
where
T: fmt::Display + 'static,
{
Value {
inner: ValueBag::capture_display(value),
}
}
/// Get a value from an error.
#[cfg(feature = "kv_unstable_std")]
pub fn capture_error<T>(err: &'v T) -> Self
where
T: std::error::Error + 'static,
{
Value {
inner: ValueBag::capture_error(err),
}
}
#[cfg(feature = "kv_unstable_serde")]
/// Get a value from a type implementing `serde::Serialize`.
pub fn capture_serde<T>(value: &'v T) -> Self
where
T: self::serde::Serialize + 'static,
{
Value {
inner: ValueBag::capture_serde1(value),
}
}
/// Get a value from a type implementing `sval::Value`.
#[cfg(feature = "kv_unstable_sval")]
pub fn capture_sval<T>(value: &'v T) -> Self
where
T: self::sval::Value + 'static,
{
Value {
inner: ValueBag::capture_sval2(value),
}
}
/// Get a value from a type implementing `std::fmt::Debug`.
pub fn from_debug<T>(value: &'v T) -> Self
where
T: fmt::Debug,
{
Value {
inner: ValueBag::from_debug(value),
}
}
/// Get a value from a type implementing `std::fmt::Display`.
pub fn from_display<T>(value: &'v T) -> Self
where
T: fmt::Display,
{
Value {
inner: ValueBag::from_display(value),
}
}
/// Get a value from a type implementing `serde::Serialize`.
#[cfg(feature = "kv_unstable_serde")]
pub fn from_serde<T>(value: &'v T) -> Self
where
T: self::serde::Serialize,
{
Value {
inner: ValueBag::from_serde1(value),
}
}
/// Get a value from a type implementing `sval::Value`.
#[cfg(feature = "kv_unstable_sval")]
pub fn from_sval<T>(value: &'v T) -> Self
where
T: self::sval::Value,
{
Value {
inner: ValueBag::from_sval2(value),
}
}
/// Get a value from a dynamic `std::fmt::Debug`.
pub fn from_dyn_debug(value: &'v dyn fmt::Debug) -> Self {
Value {
inner: ValueBag::from_dyn_debug(value),
}
}
/// Get a value from a dynamic `std::fmt::Display`.
pub fn from_dyn_display(value: &'v dyn fmt::Display) -> Self {
Value {
inner: ValueBag::from_dyn_display(value),
}
}
/// Get a value from a dynamic error.
#[cfg(feature = "kv_unstable_std")]
pub fn from_dyn_error(err: &'v (dyn std::error::Error + 'static)) -> Self {
Value {
inner: ValueBag::from_dyn_error(err),
}
}
/// Get a value from an internal primitive.
fn from_value_bag<T>(value: T) -> Self
where
T: Into<ValueBag<'v>>,
{
Value {
inner: value.into(),
}
}
/// Check whether this value can be downcast to `T`.
pub fn is<T: 'static>(&self) -> bool {
self.inner.is::<T>()
}
/// Try downcast this value to `T`.
pub fn downcast_ref<T: 'static>(&self) -> Option<&T> {
self.inner.downcast_ref::<T>()
}
/// Inspect this value using a simple visitor.
pub fn visit(&self, visitor: impl Visit<'v>) -> Result<(), Error> {
struct Visitor<V>(V);
impl<'v, V> value_bag::visit::Visit<'v> for Visitor<V>
where
V: Visit<'v>,
{
fn visit_any(&mut self, value: ValueBag) -> Result<(), value_bag::Error> {
self.0
.visit_any(Value { inner: value })
.map_err(Error::into_value)
}
fn visit_u64(&mut self, value: u64) -> Result<(), value_bag::Error> {
self.0.visit_u64(value).map_err(Error::into_value)
}
fn visit_i64(&mut self, value: i64) -> Result<(), value_bag::Error> {
self.0.visit_i64(value).map_err(Error::into_value)
}
fn visit_u128(&mut self, value: u128) -> Result<(), value_bag::Error> {
self.0.visit_u128(value).map_err(Error::into_value)
}
fn visit_i128(&mut self, value: i128) -> Result<(), value_bag::Error> {
self.0.visit_i128(value).map_err(Error::into_value)
}
fn visit_f64(&mut self, value: f64) -> Result<(), value_bag::Error> {
self.0.visit_f64(value).map_err(Error::into_value)
}
fn visit_bool(&mut self, value: bool) -> Result<(), value_bag::Error> {
self.0.visit_bool(value).map_err(Error::into_value)
}
fn visit_str(&mut self, value: &str) -> Result<(), value_bag::Error> {
self.0.visit_str(value).map_err(Error::into_value)
}
fn visit_borrowed_str(&mut self, value: &'v str) -> Result<(), value_bag::Error> {
self.0.visit_borrowed_str(value).map_err(Error::into_value)
}
fn visit_char(&mut self, value: char) -> Result<(), value_bag::Error> {
self.0.visit_char(value).map_err(Error::into_value)
}
#[cfg(feature = "kv_unstable_std")]
fn visit_error(
&mut self,
err: &(dyn std::error::Error + 'static),
) -> Result<(), value_bag::Error> {
self.0.visit_error(err).map_err(Error::into_value)
}
#[cfg(feature = "kv_unstable_std")]
fn visit_borrowed_error(
&mut self,
err: &'v (dyn std::error::Error + 'static),
) -> Result<(), value_bag::Error> {
self.0.visit_borrowed_error(err).map_err(Error::into_value)
}
}
self.inner
.visit(&mut Visitor(visitor))
.map_err(Error::from_value)
}
}
impl<'v> fmt::Debug for Value<'v> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Debug::fmt(&self.inner, f)
}
}
impl<'v> fmt::Display for Value<'v> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Display::fmt(&self.inner, f)
}
}
impl ToValue for dyn fmt::Debug {
fn to_value(&self) -> Value {
Value::from_dyn_debug(self)
}
}
impl ToValue for dyn fmt::Display {
fn to_value(&self) -> Value {
Value::from_dyn_display(self)
}
}
#[cfg(feature = "kv_unstable_std")]
impl ToValue for dyn std::error::Error + 'static {
fn to_value(&self) -> Value {
Value::from_dyn_error(self)
}
}
#[cfg(feature = "kv_unstable_serde")]
impl<'v> self::serde::Serialize for Value<'v> {
fn serialize<S>(&self, s: S) -> Result<S::Ok, S::Error>
where
S: self::serde::Serializer,
{
self.inner.serialize(s)
}
}
#[cfg(feature = "kv_unstable_sval")]
impl<'v> self::sval::Value for Value<'v> {
fn stream<'sval, S: self::sval::Stream<'sval> + ?Sized>(
&'sval self,
stream: &mut S,
) -> self::sval::Result {
self::sval::Value::stream(&self.inner, stream)
}
}
#[cfg(feature = "kv_unstable_sval")]
impl<'v> self::sval_ref::ValueRef<'v> for Value<'v> {
fn stream_ref<S: self::sval::Stream<'v> + ?Sized>(&self, stream: &mut S) -> self::sval::Result {
self::sval_ref::ValueRef::stream_ref(&self.inner, stream)
}
}
impl ToValue for str {
fn to_value(&self) -> Value {
Value::from(self)
}
}
impl ToValue for u128 {
fn to_value(&self) -> Value {
Value::from(self)
}
}
impl ToValue for i128 {
fn to_value(&self) -> Value {
Value::from(self)
}
}
impl ToValue for std::num::NonZeroU128 {
fn to_value(&self) -> Value {
Value::from(self)
}
}
impl ToValue for std::num::NonZeroI128 {
fn to_value(&self) -> Value {
Value::from(self)
}
}
impl<'v> From<&'v str> for Value<'v> {
fn from(value: &'v str) -> Self {
Value::from_value_bag(value)
}
}
impl<'v> From<&'v u128> for Value<'v> {
fn from(value: &'v u128) -> Self {
Value::from_value_bag(value)
}
}
impl<'v> From<&'v i128> for Value<'v> {
fn from(value: &'v i128) -> Self {
Value::from_value_bag(value)
}
}
impl<'v> From<&'v std::num::NonZeroU128> for Value<'v> {
fn from(v: &'v std::num::NonZeroU128) -> Value<'v> {
// SAFETY: `NonZeroU128` and `u128` have the same ABI
Value::from_value_bag(unsafe { std::mem::transmute::<&std::num::NonZeroU128, &u128>(v) })
}
}
impl<'v> From<&'v std::num::NonZeroI128> for Value<'v> {
fn from(v: &'v std::num::NonZeroI128) -> Value<'v> {
// SAFETY: `NonZeroI128` and `i128` have the same ABI
Value::from_value_bag(unsafe { std::mem::transmute::<&std::num::NonZeroI128, &i128>(v) })
}
}
impl ToValue for () {
fn to_value(&self) -> Value {
Value::from_value_bag(())
}
}
impl<T> ToValue for Option<T>
where
T: ToValue,
{
fn to_value(&self) -> Value {
match *self {
Some(ref value) => value.to_value(),
None => Value::from_value_bag(()),
}
}
}
macro_rules! impl_to_value_primitive {
($($into_ty:ty,)*) => {
$(
impl ToValue for $into_ty {
fn to_value(&self) -> Value {
Value::from(*self)
}
}
impl<'v> From<$into_ty> for Value<'v> {
fn from(value: $into_ty) -> Self {
Value::from_value_bag(value)
}
}
)*
};
}
macro_rules! impl_to_value_nonzero_primitive {
($($into_ty:ident,)*) => {
$(
impl ToValue for std::num::$into_ty {
fn to_value(&self) -> Value {
Value::from(self.get())
}
}
impl<'v> From<std::num::$into_ty> for Value<'v> {
fn from(value: std::num::$into_ty) -> Self {
Value::from(value.get())
}
}
)*
};
}
macro_rules! impl_value_to_primitive {
($(#[doc = $doc:tt] $into_name:ident -> $into_ty:ty,)*) => {
impl<'v> Value<'v> {
$(
#[doc = $doc]
pub fn $into_name(&self) -> Option<$into_ty> {
self.inner.$into_name()
}
)*
}
}
}
impl_to_value_primitive![usize, u8, u16, u32, u64, isize, i8, i16, i32, i64, f32, f64, char, bool,];
#[rustfmt::skip]
impl_to_value_nonzero_primitive![
NonZeroUsize, NonZeroU8, NonZeroU16, NonZeroU32, NonZeroU64,
NonZeroIsize, NonZeroI8, NonZeroI16, NonZeroI32, NonZeroI64,
];
impl_value_to_primitive![
#[doc = "Try convert this value into a `u64`."]
to_u64 -> u64,
#[doc = "Try convert this value into a `i64`."]
to_i64 -> i64,
#[doc = "Try convert this value into a `u128`."]
to_u128 -> u128,
#[doc = "Try convert this value into a `i128`."]
to_i128 -> i128,
#[doc = "Try convert this value into a `f64`."]
to_f64 -> f64,
#[doc = "Try convert this value into a `char`."]
to_char -> char,
#[doc = "Try convert this value into a `bool`."]
to_bool -> bool,
];
impl<'v> Value<'v> {
/// Try convert this value into an error.
#[cfg(feature = "kv_unstable_std")]
pub fn to_borrowed_error(&self) -> Option<&(dyn std::error::Error + 'static)> {
self.inner.to_borrowed_error()
}
/// Try convert this value into a borrowed string.
pub fn to_borrowed_str(&self) -> Option<&str> {
self.inner.to_borrowed_str()
}
}
#[cfg(feature = "kv_unstable_std")]
mod std_support {
use super::*;
use std::borrow::Cow;
impl<T> ToValue for Box<T>
where
T: ToValue + ?Sized,
{
fn to_value(&self) -> Value {
(**self).to_value()
}
}
impl ToValue for String {
fn to_value(&self) -> Value {
Value::from(&**self)
}
}
impl<'v> ToValue for Cow<'v, str> {
fn to_value(&self) -> Value {
Value::from(&**self)
}
}
impl<'v> Value<'v> {
/// Try convert this value into a string.
pub fn to_str(&self) -> Option<Cow<str>> {
self.inner.to_str()
}
}
impl<'v> From<&'v String> for Value<'v> {
fn from(v: &'v String) -> Self {
Value::from(&**v)
}
}
}
/// A visitor for a `Value`.
pub trait Visit<'v> {
/// Visit a `Value`.
///
/// This is the only required method on `Visit` and acts as a fallback for any
/// more specific methods that aren't overridden.
/// The `Value` may be formatted using its `fmt::Debug` or `fmt::Display` implementation,
/// or serialized using its `sval::Value` or `serde::Serialize` implementation.
fn visit_any(&mut self, value: Value) -> Result<(), Error>;
/// Visit an unsigned integer.
fn visit_u64(&mut self, value: u64) -> Result<(), Error> {
self.visit_any(value.into())
}
/// Visit a signed integer.
fn visit_i64(&mut self, value: i64) -> Result<(), Error> {
self.visit_any(value.into())
}
/// Visit a big unsigned integer.
fn visit_u128(&mut self, value: u128) -> Result<(), Error> {
self.visit_any((&value).into())
}
/// Visit a big signed integer.
fn visit_i128(&mut self, value: i128) -> Result<(), Error> {
self.visit_any((&value).into())
}
/// Visit a floating point.
fn visit_f64(&mut self, value: f64) -> Result<(), Error> {
self.visit_any(value.into())
}
/// Visit a boolean.
fn visit_bool(&mut self, value: bool) -> Result<(), Error> {
self.visit_any(value.into())
}
/// Visit a string.
fn visit_str(&mut self, value: &str) -> Result<(), Error> {
self.visit_any(value.into())
}
/// Visit a string.
fn visit_borrowed_str(&mut self, value: &'v str) -> Result<(), Error> {
self.visit_str(value)
}
/// Visit a Unicode character.
fn visit_char(&mut self, value: char) -> Result<(), Error> {
let mut b = [0; 4];
self.visit_str(&*value.encode_utf8(&mut b))
}
/// Visit an error.
#[cfg(feature = "kv_unstable_std")]
fn visit_error(&mut self, err: &(dyn std::error::Error + 'static)) -> Result<(), Error> {
self.visit_any(Value::from_dyn_error(err))
}
/// Visit an error.
#[cfg(feature = "kv_unstable_std")]
fn visit_borrowed_error(
&mut self,
err: &'v (dyn std::error::Error + 'static),
) -> Result<(), Error> {
self.visit_any(Value::from_dyn_error(err))
}
}
impl<'a, 'v, T: ?Sized> Visit<'v> for &'a mut T
where
T: Visit<'v>,
{
fn visit_any(&mut self, value: Value) -> Result<(), Error> {
(**self).visit_any(value)
}
fn visit_u64(&mut self, value: u64) -> Result<(), Error> {
(**self).visit_u64(value)
}
fn visit_i64(&mut self, value: i64) -> Result<(), Error> {
(**self).visit_i64(value)
}
fn visit_u128(&mut self, value: u128) -> Result<(), Error> {
(**self).visit_u128(value)
}
fn visit_i128(&mut self, value: i128) -> Result<(), Error> {
(**self).visit_i128(value)
}
fn visit_f64(&mut self, value: f64) -> Result<(), Error> {
(**self).visit_f64(value)
}
fn visit_bool(&mut self, value: bool) -> Result<(), Error> {
(**self).visit_bool(value)
}
fn visit_str(&mut self, value: &str) -> Result<(), Error> {
(**self).visit_str(value)
}
fn visit_borrowed_str(&mut self, value: &'v str) -> Result<(), Error> {
(**self).visit_borrowed_str(value)
}
fn visit_char(&mut self, value: char) -> Result<(), Error> {
(**self).visit_char(value)
}
#[cfg(feature = "kv_unstable_std")]
fn visit_error(&mut self, err: &(dyn std::error::Error + 'static)) -> Result<(), Error> {
(**self).visit_error(err)
}
#[cfg(feature = "kv_unstable_std")]
fn visit_borrowed_error(
&mut self,
err: &'v (dyn std::error::Error + 'static),
) -> Result<(), Error> {
(**self).visit_borrowed_error(err)
}
}
#[cfg(test)]
pub(crate) mod tests {
use super::*;
pub(crate) use super::value_bag::test::TestToken as Token;
impl<'v> Value<'v> {
pub(crate) fn to_token(&self) -> Token {
self.inner.to_test_token()
}
}
fn unsigned() -> impl Iterator<Item = Value<'static>> {
vec![
Value::from(8u8),
Value::from(16u16),
Value::from(32u32),
Value::from(64u64),
Value::from(1usize),
Value::from(std::num::NonZeroU8::new(8).unwrap()),
Value::from(std::num::NonZeroU16::new(16).unwrap()),
Value::from(std::num::NonZeroU32::new(32).unwrap()),
Value::from(std::num::NonZeroU64::new(64).unwrap()),
Value::from(std::num::NonZeroUsize::new(1).unwrap()),
]
.into_iter()
}
fn signed() -> impl Iterator<Item = Value<'static>> {
vec![
Value::from(-8i8),
Value::from(-16i16),
Value::from(-32i32),
Value::from(-64i64),
Value::from(-1isize),
Value::from(std::num::NonZeroI8::new(-8).unwrap()),
Value::from(std::num::NonZeroI16::new(-16).unwrap()),
Value::from(std::num::NonZeroI32::new(-32).unwrap()),
Value::from(std::num::NonZeroI64::new(-64).unwrap()),
Value::from(std::num::NonZeroIsize::new(-1).unwrap()),
]
.into_iter()
}
fn float() -> impl Iterator<Item = Value<'static>> {
vec![Value::from(32.32f32), Value::from(64.64f64)].into_iter()
}
fn bool() -> impl Iterator<Item = Value<'static>> {
vec![Value::from(true), Value::from(false)].into_iter()
}
fn str() -> impl Iterator<Item = Value<'static>> {
vec![Value::from("a string"), Value::from("a loong string")].into_iter()
}
fn char() -> impl Iterator<Item = Value<'static>> {
vec![Value::from('a'), Value::from('â›°')].into_iter()
}
#[test]
fn test_capture_fmt() {
assert_eq!(Some(42u64), Value::capture_display(&42).to_u64());
assert_eq!(Some(42u64), Value::capture_debug(&42).to_u64());
assert!(Value::from_display(&42).to_u64().is_none());
assert!(Value::from_debug(&42).to_u64().is_none());
}
#[cfg(feature = "kv_unstable_std")]
#[test]
fn test_capture_error() {
let err = std::io::Error::from(std::io::ErrorKind::Other);
assert!(Value::capture_error(&err).to_borrowed_error().is_some());
assert!(Value::from_dyn_error(&err).to_borrowed_error().is_some());
}
#[cfg(feature = "kv_unstable_serde")]
#[test]
fn test_capture_serde() {
assert_eq!(Some(42u64), Value::capture_serde(&42).to_u64());
assert_eq!(Some(42u64), Value::from_serde(&42).to_u64());
}
#[cfg(feature = "kv_unstable_sval")]
#[test]
fn test_capture_sval() {
assert_eq!(Some(42u64), Value::capture_sval(&42).to_u64());
assert_eq!(Some(42u64), Value::from_sval(&42).to_u64());
}
#[test]
fn test_to_value_display() {
assert_eq!(42u64.to_value().to_string(), "42");
assert_eq!(42i64.to_value().to_string(), "42");
assert_eq!(42.01f64.to_value().to_string(), "42.01");
assert_eq!(true.to_value().to_string(), "true");
assert_eq!('a'.to_value().to_string(), "a");
assert_eq!("a loong string".to_value().to_string(), "a loong string");
assert_eq!(Some(true).to_value().to_string(), "true");
assert_eq!(().to_value().to_string(), "None");
assert_eq!(Option::None::<bool>.to_value().to_string(), "None");
}
#[test]
fn test_to_value_structured() {
assert_eq!(42u64.to_value().to_token(), Token::U64(42));
assert_eq!(42i64.to_value().to_token(), Token::I64(42));
assert_eq!(42.01f64.to_value().to_token(), Token::F64(42.01));
assert_eq!(true.to_value().to_token(), Token::Bool(true));
assert_eq!('a'.to_value().to_token(), Token::Char('a'));
assert_eq!(
"a loong string".to_value().to_token(),
Token::Str("a loong string".into())
);
assert_eq!(Some(true).to_value().to_token(), Token::Bool(true));
assert_eq!(().to_value().to_token(), Token::None);
assert_eq!(Option::None::<bool>.to_value().to_token(), Token::None);
}
#[test]
fn test_to_number() {
for v in unsigned() {
assert!(v.to_u64().is_some());
assert!(v.to_i64().is_some());
}
for v in signed() {
assert!(v.to_i64().is_some());
}
for v in unsigned().chain(signed()).chain(float()) {
assert!(v.to_f64().is_some());
}
for v in bool().chain(str()).chain(char()) {
assert!(v.to_u64().is_none());
assert!(v.to_i64().is_none());
assert!(v.to_f64().is_none());
}
}
#[test]
fn test_to_str() {
for v in str() {
assert!(v.to_borrowed_str().is_some());
#[cfg(feature = "kv_unstable_std")]
assert!(v.to_str().is_some());
}
let short_lived = String::from("short lived");
let v = Value::from(&*short_lived);
assert!(v.to_borrowed_str().is_some());
#[cfg(feature = "kv_unstable_std")]
assert!(v.to_str().is_some());
for v in unsigned().chain(signed()).chain(float()).chain(bool()) {
assert!(v.to_borrowed_str().is_none());
#[cfg(feature = "kv_unstable_std")]
assert!(v.to_str().is_none());
}
}
#[test]
fn test_to_bool() {
for v in bool() {
assert!(v.to_bool().is_some());
}
for v in unsigned()
.chain(signed())
.chain(float())
.chain(str())
.chain(char())
{
assert!(v.to_bool().is_none());
}
}
#[test]
fn test_to_char() {
for v in char() {
assert!(v.to_char().is_some());
}
for v in unsigned()
.chain(signed())
.chain(float())
.chain(str())
.chain(bool())
{
assert!(v.to_char().is_none());
}
}
#[test]
fn test_downcast_ref() {
#[derive(Debug)]
struct Foo(u64);
let v = Value::capture_debug(&Foo(42));
assert!(v.is::<Foo>());
assert_eq!(42u64, v.downcast_ref::<Foo>().expect("invalid downcast").0);
}
#[test]
fn test_visit_integer() {
struct Extract(Option<u64>);
impl<'v> Visit<'v> for Extract {
fn visit_any(&mut self, value: Value) -> Result<(), Error> {
unimplemented!("unexpected value: {:?}", value)
}
fn visit_u64(&mut self, value: u64) -> Result<(), Error> {
self.0 = Some(value);
Ok(())
}
}
let mut extract = Extract(None);
Value::from(42u64).visit(&mut extract).unwrap();
assert_eq!(Some(42), extract.0);
}
#[test]
fn test_visit_borrowed_str() {
struct Extract<'v>(Option<&'v str>);
impl<'v> Visit<'v> for Extract<'v> {
fn visit_any(&mut self, value: Value) -> Result<(), Error> {
unimplemented!("unexpected value: {:?}", value)
}
fn visit_borrowed_str(&mut self, value: &'v str) -> Result<(), Error> {
self.0 = Some(value);
Ok(())
}
}
let mut extract = Extract(None);
let short_lived = String::from("A short-lived string");
Value::from(&*short_lived).visit(&mut extract).unwrap();
assert_eq!(Some("A short-lived string"), extract.0);
}
}