Store parameter usage metadata in benchmark results

src/benchmark/benchmark_result.rs

@@ -2,6 +2,15 @@ use std::collections::BTreeMap;
 
 use serde::Serialize;
 
+/// Parameter value and whether it was used in the command line template
+#[derive(Debug, Default, Clone, Serialize, PartialEq)]
+#[serde(transparent)]
+pub struct Parameter {
+    pub value: String,
+    #[serde(skip)]
+    pub is_unused: bool,
+}
+
 /// Set of values that will be exported.
 // NOTE: `serde` is used for JSON serialization, but not for CSV serialization due to the
 // `parameters` map. Update `src/hyperfine/export/csv.rs` with new fields, as appropriate.
@@ -49,5 +58,5 @@ pub struct BenchmarkResult {
 
     /// Parameter values for this benchmark
     #[serde(skip_serializing_if = "BTreeMap::is_empty")]
-    pub parameters: BTreeMap<String, String>,
+    pub parameters: BTreeMap<String, Parameter>,
 }

src/benchmark/mod.rs

@@ -19,7 +19,7 @@ use crate::output::warnings::{OutlierWarningOptions, Warnings};
 use crate::parameter::ParameterNameAndValue;
 use crate::quantity::{byte, const_time_from_seconds, ratio, second, FormatQuantity, Time, Zero};
 use crate::util::exit_code::extract_exit_code;
-use benchmark_result::BenchmarkResult;
+use benchmark_result::{BenchmarkResult, Parameter};
 use measurement::{Measurement, Measurements};
 
 use anyhow::{anyhow, Result};
@@ -474,7 +474,15 @@ impl<'a> Benchmark<'a> {
                 .command
                 .get_parameters()
                 .iter()
-                .map(|(name, value)| (name.to_string(), value.to_string()))
+                .map(|(name, value)| {
+                    (
+                        name.to_string(),
+                        Parameter {
+                            value: value.to_string(),
+                            is_unused: self.command.is_parameter_unused(name),
+                        },
+                    )
+                })
                 .collect(),
         })
     }