Fix ok_or which used format_err, causing perf problems with debug…

… builds

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "wmi"
-version = "0.4.3"
+version = "0.4.4"
 authors = ["Ohad Ravid <[email protected]>"]
 edition = "2018"
 license = "MIT OR Apache-2.0"

src/benches/benchmark.rs

@@ -57,6 +57,16 @@ pub struct ProcessExecutable {
     pub Dependent: String,
 }
 
+#[derive(Serialize, Deserialize, Debug)]
+#[serde(rename = "Win32_Service")]
+pub struct Service {
+    pub Name: String,
+    pub DisplayName: String,
+    pub PathName: Option<String>,
+    pub State: String,
+    pub Started: bool,
+}
+
 fn get_accounts(con: &WMIConnection) {
     let accounts: Vec<Account> = con.query().unwrap();
 }
@@ -94,6 +104,10 @@ pub fn get_modules(con: &WMIConnection) {
     let execs: Vec<ProcessExecutable> = con.query().unwrap();
 }
 
+fn get_services(con: &WMIConnection) {
+    let services: Vec<Service> = con.query().unwrap();
+}
+
 fn criterion_benchmark(c: &mut Criterion) {
     // baseline: 41ms
     c.bench_function("get_accounts", |b| {
@@ -137,6 +151,12 @@ fn criterion_benchmark(c: &mut Criterion) {
         let wmi_con = WMIConnection::new(COMLibrary::new().unwrap().into()).unwrap();
         b.iter(|| get_modules(&wmi_con))
     });
+
+    // baseline: 300ms.
+    c.bench_function("get_services", |b| {
+        let wmi_con = WMIConnection::new(COMLibrary::new().unwrap().into()).unwrap();
+        b.iter(|| get_services(&wmi_con))
+    });
 }
 
 criterion_group!(benches, criterion_benchmark);

src/de/wbem_class_de.rs

@@ -142,7 +142,7 @@ where
         let current_field = self
             .fields
             .next()
-            .ok_or(format_err!("Expected current field to not be None"))?;
+            .ok_or_else(|| format_err!("Expected current field to not be None"))?;
 
         let property_value = self
             .de