Disable some code (and fix others) when no features are enabled

src/error.rs

@@ -1,4 +1,8 @@
-use std::{fmt, path::PathBuf};
+use std::fmt;
+
+#[cfg(any(feature = "toml", feature = "yaml"))]
+use std::path::PathBuf;
+
 
 
 /// Type describing all errors that can occur in this library.
@@ -13,12 +17,14 @@ pub(crate) enum ErrorInner {
     MissingValue(String),
 
     /// An IO error occured, e.g. when reading a file.
+    #[cfg(any(feature = "toml", feature = "yaml"))]
     Io {
         path: Option<PathBuf>,
         err: std::io::Error,
     },
 
     /// Returned by `Source::load` implementations when deserialization fails.
+    #[cfg(any(feature = "toml", feature = "yaml"))]
     Deserialization {
         /// A human readable description for the error message, describing from
         /// what source it was attempted to deserialize. Completes the sentence
@@ -39,17 +45,20 @@ pub(crate) enum ErrorInner {
     /// Returned by the [`Source`] impls for `Path` and `PathBuf` if the file
     /// extension is not supported by confique or if the corresponding Cargo
     /// feature of confique was not enabled.
+    #[cfg(any(feature = "toml", feature = "yaml"))]
     UnsupportedFileFormat {
         path: PathBuf,
     },
 
     /// Returned by the [`Source`] impls for `Path` and `PathBuf` if the path
     /// does not contain a file extension.
+    #[cfg(any(feature = "toml", feature = "yaml"))]
     MissingFileExtension {
         path: PathBuf,
     },
 
     /// A file source was marked as required but the file does not exist.
+    #[cfg(any(feature = "toml", feature = "yaml"))]
     MissingRequiredFile {
         path: PathBuf,
     }
@@ -58,13 +67,18 @@ pub(crate) enum ErrorInner {
 impl std::error::Error for Error {
     fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
         match &*self.inner {
+            #[cfg(any(feature = "toml", feature = "yaml"))]
             ErrorInner::Io { err, .. } => Some(err),
+            #[cfg(any(feature = "toml", feature = "yaml"))]
             ErrorInner::Deserialization { err, .. } => Some(&**err),
-            ErrorInner::MissingValue(_)
-            | ErrorInner::EnvDeserialization { .. }
-            | ErrorInner::UnsupportedFileFormat { .. }
-            | ErrorInner::MissingFileExtension { .. }
-            | ErrorInner::MissingRequiredFile { .. } => None,
+            ErrorInner::MissingValue(_) => None,
+            ErrorInner::EnvDeserialization { .. } => None,
+            #[cfg(any(feature = "toml", feature = "yaml"))]
+            ErrorInner::UnsupportedFileFormat { .. } => None,
+            #[cfg(any(feature = "toml", feature = "yaml"))]
+            ErrorInner::MissingFileExtension { .. } => None,
+            #[cfg(any(feature = "toml", feature = "yaml"))]
+            ErrorInner::MissingRequiredFile { .. } => None,
         }
     }
 }
@@ -75,18 +89,22 @@ impl fmt::Display for Error {
             ErrorInner::MissingValue(path) => {
                 std::write!(f, "required configuration value is missing: '{}'", path)
             }
+            #[cfg(any(feature = "toml", feature = "yaml"))]
             ErrorInner::Io { path: Some(path), .. } => {
                 std::write!(f,
                     "IO error occured while reading configuration file '{}'",
                     path.display(),
                 )
             }
+            #[cfg(any(feature = "toml", feature = "yaml"))]
             ErrorInner::Io { path: None, .. } => {
                 std::write!(f, "IO error occured while loading configuration")
             }
+            #[cfg(any(feature = "toml", feature = "yaml"))]
             ErrorInner::Deserialization { source: Some(source), .. } => {
                 std::write!(f, "failed to deserialize configuration from {}", source)
             }
+            #[cfg(any(feature = "toml", feature = "yaml"))]
             ErrorInner::Deserialization { source: None, .. } => {
                 std::write!(f, "failed to deserialize configuration")
             }
@@ -98,18 +116,21 @@ impl fmt::Display for Error {
                     msg,
                 )
             }
+            #[cfg(any(feature = "toml", feature = "yaml"))]
             ErrorInner::UnsupportedFileFormat { path } => {
                 std::write!(f,
                     "unknown configuration file format/extension: '{}'",
                     path.display(),
                 )
             }
+            #[cfg(any(feature = "toml", feature = "yaml"))]
             ErrorInner::MissingFileExtension { path } => {
                 std::write!(f,
                     "cannot guess configuration file format due to missing file extension in '{}'",
                     path.display(),
                 )
             }
+            #[cfg(any(feature = "toml", feature = "yaml"))]
             ErrorInner::MissingRequiredFile { path } => {
                 std::write!(f,
                     "required configuration file does not exist: '{}'",