Replace no_std feature with std feature

.github/workflows/build.yml

@@ -14,7 +14,7 @@ jobs:
     strategy:
       matrix:
         rust: [stable]
-        FEATURES: ['', 'from_str', 'no_std']
+        FEATURES: ['', 'from_str', 'std']
 
         include:
           # Test nightly but don't fail
@@ -62,7 +62,7 @@ jobs:
       - uses: actions-rs/cargo@v1
         with:
           command: build
-          args: --target=${{ matrix.TARGET }} --features no_std
+          args: --target=${{ matrix.TARGET }}
 
   fmt:
     runs-on: ubuntu-latest
@@ -83,7 +83,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        FEATURES: ['', 'from_str', 'no_std']
+        FEATURES: ['', 'from_str', 'std']
     steps:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1

CHANGELOG.md

@@ -6,6 +6,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
+### Changed
+
+- Replaced the `no_std` feature with an additive `std` feature, fixing problems with serde serialization on `no_std` targets.
+
 ## [0.10.4]
 
 ### Added

Cargo.toml

@@ -15,10 +15,10 @@ license = "MIT"
 readme = "README.md"
 
 [features]
-no_std = [ "libm" ]
-from_str = ["regex"]
+std = []
+from_str = ["regex", "std"]
 
 [dependencies]
-serde = { version = "1.0", optional = true, features = ["derive"] }
+serde = { version = "1.0", optional = true, default-features = false, features = ["derive"] }
 regex = { version = "1", optional = true }
-libm = { version = "0.2", optional = true }
+libm = { version = "0.2" }

README.md

@@ -89,8 +89,8 @@ fn main() {
 
 The crate contains few features to disable or enable certain functionalities:
 
-* no_std
-    * Removes functionality that Rust std library provides
+* `std`
+    * Enables functionality that Rust standard library provides instead of using `libm` for some math functions
 * from_str
     * Allows creating measurement units from string input
 

src/angle.rs

@@ -47,43 +47,43 @@ impl Angle {
     }
 
     /// Calculate the cosine of this angle
-    #[cfg(not(feature = "no_std"))]
+    #[cfg(feature = "std")]
     pub fn cos(&self) -> f64 {
         self.radians.cos()
     }
 
     /// Calculate the sine of this angle
-    #[cfg(not(feature = "no_std"))]
+    #[cfg(feature = "std")]
     pub fn sin(&self) -> f64 {
         self.radians.sin()
     }
 
     /// Calculate the sine and cosine of this angle
-    #[cfg(not(feature = "no_std"))]
+    #[cfg(feature = "std")]
     pub fn sin_cos(&self) -> (f64, f64) {
         self.radians.sin_cos()
     }
 
     /// Calculate the tangent of this angle
-    #[cfg(not(feature = "no_std"))]
+    #[cfg(feature = "std")]
     pub fn tan(&self) -> f64 {
         self.radians.tan()
     }
 
     /// Calculate the arcsine of a number
-    #[cfg(not(feature = "no_std"))]
+    #[cfg(feature = "std")]
     pub fn asin(num: f64) -> Self {
         Angle::from_radians(num.asin())
     }
 
     /// Calculate the arccosine of a number
-    #[cfg(not(feature = "no_std"))]
+    #[cfg(feature = "std")]
     pub fn acos(num: f64) -> Self {
         Angle::from_radians(num.acos())
     }
 
     /// Calculate the arctangent of a number
-    #[cfg(not(feature = "no_std"))]
+    #[cfg(feature = "std")]
     pub fn atan(num: f64) -> Self {
         Angle::from_radians(num.atan())
     }

src/humidity.rs

@@ -69,7 +69,7 @@ impl Humidity {
     /// Calculates Dewpoint from humidity and air temperature using the Magnus-Tetens
     /// approximation, with coefficients derived by Alduchov and Eskridge (1996). The formulas assume
     //  standard atmospheric pressure.
-    #[cfg(not(feature = "no_std"))]
+    #[cfg(feature = "std")]
     pub fn as_dewpoint(&self, temp: Temperature) -> Temperature {
         let humidity = self.relative_humidity / 100.0;
         let celsius = temp.as_celsius();
@@ -81,7 +81,7 @@ impl Humidity {
     /// Calculates Dewpoint from humidity and air temperature using the Magnus-Tetens
     /// approximation, with coefficients derived by Alduchov and Eskridge (1996). The formulas assume
     //  standard atmospheric pressure.
-    #[cfg(feature = "no_std")]
+    #[cfg(not(feature = "std"))]
     pub fn as_dewpoint(&self, temp: Temperature) -> Temperature {
         let humidity = self.relative_humidity / 100.0;
         let celsius = temp.as_celsius();
@@ -94,7 +94,7 @@ impl Humidity {
     /// Calculates the actual vapour pressure in the air, based on the air temperature and humidity
     /// at standard atmospheric pressure (1013.25 mb), using the Buck formula (accurate to +/- 0.02%
     /// between 0 deg C and 50 deg C)
-    #[cfg(not(feature = "no_std"))]
+    #[cfg(feature = "std")]
     pub fn as_vapor_pressure(&self, temp: Temperature) -> Pressure {
         let temp = temp.as_celsius();
         let saturation_vapor_pressure =
@@ -105,7 +105,7 @@ impl Humidity {
     /// Calculates the actual vapour pressure in the air, based on the air temperature and humidity
     /// at standard atmospheric pressure (1013.25 mb), using the Buck formula (accurate to +/- 0.02%
     /// between 0 deg C and 50 deg C)
-    #[cfg(feature = "no_std")]
+    #[cfg(not(feature = "std"))]
     pub fn as_vapor_pressure(&self, temp: Temperature) -> Pressure {
         let temp = temp.as_celsius();
         let saturation_vapor_pressure =
@@ -125,7 +125,7 @@ impl Humidity {
     /// Calculates humidity from dewpoint and air temperature using the Magnus-Tetens
     /// Approximation, with coefficients derived by Alduchov and Eskridge (1996). The formulas assume
     //  standard atmospheric pressure.
-    #[cfg(not(feature = "no_std"))]
+    #[cfg(feature = "std")]
     pub fn from_dewpoint(dewpoint: Temperature, temp: Temperature) -> Humidity {
         let dewpoint = dewpoint.as_celsius();
         let temp = temp.as_celsius();
@@ -138,7 +138,7 @@ impl Humidity {
     /// Calculates humidity from dewpoint and air temperature using the Magnus-Tetens
     /// Approximation, with coefficients derived by Alduchov and Eskridge (1996). The formulas assume
     //  standard atmospheric pressure.
-    #[cfg(feature = "no_std")]
+    #[cfg(not(feature = "std"))]
     pub fn from_dewpoint(dewpoint: Temperature, temp: Temperature) -> Humidity {
         let dewpoint = dewpoint.as_celsius();
         let temp = temp.as_celsius();

src/lib.rs

@@ -7,14 +7,14 @@
 //! by an Area to get a Pressure.
 
 #![deny(warnings, missing_docs)]
-#![cfg_attr(feature = "no_std", no_std)]
+#![cfg_attr(not(feature = "std"), no_std)]
 
-#[cfg(feature = "no_std")]
+#[cfg(not(feature = "std"))]
 use core as std;
-#[cfg(feature = "no_std")]
+#[cfg(not(feature = "std"))]
 use core::time;
 
-#[cfg(not(feature = "no_std"))]
+#[cfg(feature = "std")]
 use std::time;
 
 #[cfg(feature = "serde")]