Fix imports on features +alloc +raw_value -std

Closes #850.

Author: dtolnay

.github/workflows/ci.yml

@@ -49,6 +49,7 @@ jobs:
       - run: cargo check --features raw_value
       - run: cargo check --features unbounded_depth
       - run: cargo check --manifest-path tests/crate/Cargo.toml --no-default-features --features alloc
+      - run: cargo check --manifest-path tests/crate/Cargo.toml --no-default-features --features alloc,raw_value
       - run: cargo check --features preserve_order
         if: matrix.rust != '1.45.0' && matrix.rust != '1.40.0' && matrix.rust != '1.38.0' && matrix.rust != '1.36.0'
       - run: cargo check --manifest-path tests/crate/Cargo.toml --no-default-features --features alloc,preserve_order

src/raw.rs

@@ -1,4 +1,7 @@
 use crate::error::Error;
+use alloc::borrow::ToOwned;
+use alloc::boxed::Box;
+use alloc::string::String;
 use core::fmt::{self, Debug, Display};
 use core::mem;
 use serde::de::value::BorrowedStrDeserializer;

src/value/de.rs

@@ -4,6 +4,8 @@ use crate::number::Number;
 use crate::value::Value;
 use alloc::borrow::{Cow, ToOwned};
 use alloc::string::String;
+#[cfg(feature = "raw_value")]
+use alloc::string::ToString;
 use alloc::vec::{self, Vec};
 use core::fmt;
 use core::slice;