From 0edfa81f2f7ebf81e3734c3021dbed32f3a4ca67 Mon Sep 17 00:00:00 2001
From: scoobybejesus <scoobybejesus@users.noreply.github.com>
Date: Tue, 24 Sep 2019 12:02:22 -0400
Subject: [PATCH] Substituted Vec::with_capacity() where able.

---
 src/csv_export.rs            | 32 ++++++++++++++++----------------
 src/csv_import_accts_txns.rs |  4 ++--
 2 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/src/csv_export.rs b/src/csv_export.rs
index 5369c29..35aecd8 100644
--- a/src/csv_export.rs
+++ b/src/csv_export.rs
@@ -19,8 +19,8 @@ pub fn _1_account_sums_to_csv(
     acct_map: &HashMap<u16, Account>
 ) {
 
-    let mut rows: Vec<Vec<String>> = [].to_vec();
-    let mut header: Vec<String> = [].to_vec();
+    let mut rows: Vec<Vec<String>> = Vec::with_capacity(acct_map.len());
+    let mut header: Vec<String> = Vec::with_capacity(5);
 
     header.extend_from_slice(&[
         "Account".to_string(),
@@ -36,7 +36,7 @@ pub fn _1_account_sums_to_csv(
     for j in 1..=length {
 
         let acct = acct_map.get(&(j as u16)).unwrap();
-        let mut row: Vec<String> = [].to_vec();
+        let mut row: Vec<String> = Vec::with_capacity(5);
 
         let balance: String;
         let tentative_balance = acct.get_sum_of_amts_in_lots();
@@ -81,8 +81,8 @@ pub fn _2_account_sums_nonzero_to_csv(
     raw_acct_map: &HashMap<u16, RawAccount>
 ) {
 
-    let mut rows: Vec<Vec<String>> = [].to_vec();
-    let mut header: Vec<String> = [].to_vec();
+    let mut rows: Vec<Vec<String>> = Vec::with_capacity(acct_map.len());    //  more than needed...
+    let mut header: Vec<String> = Vec::with_capacity(5);
 
     header.extend_from_slice(&[
         "Account".to_string(),
@@ -98,7 +98,7 @@ pub fn _2_account_sums_nonzero_to_csv(
     for j in 1..=length {
 
         let acct = acct_map.get(&(j as u16)).unwrap();
-        let mut row: Vec<String> = [].to_vec();
+        let mut row: Vec<String> = Vec::with_capacity(5);
 
         let raw_acct = raw_acct_map.get(&acct.raw_key).unwrap();
         let name = raw_acct.name.to_string();
@@ -149,8 +149,8 @@ pub fn _3_account_sums_to_csv_with_orig_basis(
     acct_map: &HashMap<u16, Account>
 ) {
 
-    let mut rows: Vec<Vec<String>> = [].to_vec();
-    let mut header: Vec<String> = [].to_vec();
+    let mut rows: Vec<Vec<String>> = Vec::with_capacity(acct_map.len());
+    let mut header: Vec<String> = Vec::with_capacity(6);
 
     header.extend_from_slice(&[
         "Account".to_string(),
@@ -167,7 +167,7 @@ pub fn _3_account_sums_to_csv_with_orig_basis(
     for j in 1..=length {
 
         let acct = acct_map.get(&(j as u16)).unwrap();
-        let mut row: Vec<String> = [].to_vec();
+        let mut row: Vec<String> = Vec::with_capacity(6);
 
         let balance: String;
         let tentative_balance = acct.get_sum_of_amts_in_lots();
@@ -228,7 +228,7 @@ pub fn _4_transaction_mvmt_detail_to_csv(
 ) -> Result<(), Box<dyn Error>> {
 
     let mut rows: Vec<Vec<String>> = [].to_vec();
-    let mut header: Vec<String> = [].to_vec();
+    let mut header: Vec<String> = Vec::with_capacity(12);
     header.extend_from_slice(&[
         "Date".to_string(),
         "Txn#".to_string(),
@@ -285,7 +285,7 @@ pub fn _4_transaction_mvmt_detail_to_csv(
                 gain_loss = d128!(0);
             }
 
-            let mut row: Vec<String> = [].to_vec();
+            let mut row: Vec<String> = Vec::with_capacity(12);
 
             row.push(date);
             row.push("Txn ".to_string() + &tx_number);
@@ -327,7 +327,7 @@ pub fn _5_transaction_mvmt_summaries_to_csv(
 ) -> Result<(), Box<dyn Error>> {
 
     let mut rows: Vec<Vec<String>> = [].to_vec();
-    let mut header: Vec<String> = [].to_vec();
+    let mut header: Vec<String> = Vec::with_capacity(12);
 
     header.extend_from_slice(&[
         "Date".to_string(),
@@ -441,7 +441,7 @@ pub fn _5_transaction_mvmt_summaries_to_csv(
 
         if let Some(term) = term_st {
 
-            let mut row: Vec<String> = [].to_vec();
+            let mut row: Vec<String> = Vec::with_capacity(12);
 
             row.push(txn_date_string.clone());
             row.push(tx_num_string.clone());
@@ -460,7 +460,7 @@ pub fn _5_transaction_mvmt_summaries_to_csv(
         }
         if let Some(term) = term_lt {
 
-            let mut row: Vec<String> = [].to_vec();
+            let mut row: Vec<String> = Vec::with_capacity(12);
 
             row.push(txn_date_string);
             row.push(tx_num_string);
@@ -503,7 +503,7 @@ pub fn _6_transaction_mvmt_detail_to_csv_w_orig(
 ) -> Result<(), Box<dyn Error>> {
 
     let mut rows: Vec<Vec<String>> = [].to_vec();
-    let mut header: Vec<String> = [].to_vec();
+    let mut header: Vec<String> = Vec::with_capacity(16);
     header.extend_from_slice(&[
         "Date".to_string(),
         "Txn#".to_string(),
@@ -571,7 +571,7 @@ pub fn _6_transaction_mvmt_detail_to_csv_w_orig(
                 orig_gain_loss = d128!(0);
             }
 
-            let mut row: Vec<String> = [].to_vec();
+            let mut row: Vec<String> = Vec::with_capacity(16);
 
             row.push(date);
             row.push("Txn ".to_string() + &tx_number);
diff --git a/src/csv_import_accts_txns.rs b/src/csv_import_accts_txns.rs
index aa32c9e..5d57f46 100644
--- a/src/csv_import_accts_txns.rs
+++ b/src/csv_import_accts_txns.rs
@@ -27,7 +27,7 @@ pub(crate) fn import_accounts(
     let header4: csv::StringRecord; //  is_margin
 
     // A StringRecord doesn't accept the same range indexing we need below, so we create our own
-    let mut headerstrings: Vec<String> = [].to_vec();
+    let mut headerstrings: Vec<String> = Vec::with_capacity(header1.len());
 
     for element in header1.into_iter() {
         headerstrings.push(element.to_string())
@@ -134,7 +134,7 @@ pub(crate) fn import_transactions(
         let mut proceeds_parsed = 0f32;
 
         //  Next, create action_records.
-        let mut action_records_map_keys_vec: Vec<u32> = [].to_vec();
+        let mut action_records_map_keys_vec: Vec<u32> = Vec::with_capacity(2);
         let mut outgoing_ar: Option<ActionRecord> = None;
         let mut incoming_ar: Option<ActionRecord> = None;
         let mut outgoing_ar_num: Option<u32> = None;