A bunch of clang-tidy fixes.

Change-Id: I1442d69eb9be91a8c368187848d65196273e3de6
diff --git a/internal/ceres/block_sparse_matrix_test.cc b/internal/ceres/block_sparse_matrix_test.cc
index 7b64a7c..7fab13a 100644
--- a/internal/ceres/block_sparse_matrix_test.cc
+++ b/internal/ceres/block_sparse_matrix_test.cc
@@ -45,7 +45,7 @@
 namespace internal {
 
 namespace {
-template<typename T>
+template <typename T>
 void CheckVectorEq(const std::vector<T>& a, const std::vector<T>& b) {
   EXPECT_EQ(a.size(), b.size());
   for (int i = 0; i < a.size(); ++i) {
@@ -62,24 +62,20 @@
     // [ 0 0 8 9 10 0 ]
     CompressedRowBlockStructure* bs = new CompressedRowBlockStructure;
     bs->cols = {
-      // Block size 2, position 0.
-      Block(2, 0),
-      // Block size 3, position 2.
-      Block(3, 2),
-      // Block size 1, position 5.
-      Block(1, 5),
+        // Block size 2, position 0.
+        Block(2, 0),
+        // Block size 3, position 2.
+        Block(3, 2),
+        // Block size 1, position 5.
+        Block(1, 5),
     };
-    bs->rows = {
-      CompressedRow(1),
-      CompressedRow(1)
-    };
+    bs->rows = {CompressedRow(1), CompressedRow(1)};
     bs->rows[0].block = Block(2, 0);
-    bs->rows[0].cells = { Cell(0, 0) };
+    bs->rows[0].cells = {Cell(0, 0)};
 
     bs->rows[1].block = Block(2, 2);
-    bs->rows[1].cells = { Cell(1, 4) };
-    std::unique_ptr<BlockSparseMatrix> m =
-        std::make_unique<BlockSparseMatrix>(bs);
+    bs->rows[1].cells = {Cell(1, 4)};
+    auto m = std::make_unique<BlockSparseMatrix>(bs);
     EXPECT_NE(m, nullptr);
     EXPECT_EQ(m->num_rows(), 4);
     EXPECT_EQ(m->num_cols(), 6);
@@ -96,26 +92,22 @@
     // [ 0 0 9 0 0 0 ]
     CompressedRowBlockStructure* bs = new CompressedRowBlockStructure;
     bs->cols = {
-      // Block size 2, position 0.
-      Block(2, 0),
-      // Block size 1, position 2.
-      Block(1, 2),
-      // Block size 2, position 3.
-      Block(2, 3),
-      // Block size 1, position 5.
-      Block(1, 5),
+        // Block size 2, position 0.
+        Block(2, 0),
+        // Block size 1, position 2.
+        Block(1, 2),
+        // Block size 2, position 3.
+        Block(2, 3),
+        // Block size 1, position 5.
+        Block(1, 5),
     };
-    bs->rows = {
-      CompressedRow(2),
-      CompressedRow(1)
-    };
+    bs->rows = {CompressedRow(2), CompressedRow(1)};
     bs->rows[0].block = Block(2, 0);
-    bs->rows[0].cells = { Cell(0, 0), Cell(2, 4) };
+    bs->rows[0].cells = {Cell(0, 0), Cell(2, 4)};
 
     bs->rows[1].block = Block(1, 2);
-    bs->rows[1].cells = { Cell(1, 8) };
-    std::unique_ptr<BlockSparseMatrix> m =
-        std::make_unique<BlockSparseMatrix>(bs);
+    bs->rows[1].cells = {Cell(1, 8)};
+    auto m = std::make_unique<BlockSparseMatrix>(bs);
     EXPECT_NE(m, nullptr);
     EXPECT_EQ(m->num_rows(), 3);
     EXPECT_EQ(m->num_cols(), 6);
@@ -309,10 +301,8 @@
     EXPECT_EQ(m_dense.rows(), 4);
     EXPECT_EQ(m_dense.cols(), 6);
     Matrix m_expected(4, 6);
-    m_expected << 1, 2, 0, 0, 0, 0,
-                  3, 4, 0, 0, 0, 0,
-                  0, 0, 5, 6, 7, 0,
-                  0, 0, 8, 9, 10, 0;
+    m_expected << 1, 2, 0, 0, 0, 0, 3, 4, 0, 0, 0, 0, 0, 0, 5, 6, 7, 0, 0, 0, 8,
+        9, 10, 0;
     EXPECT_EQ(m_dense, m_expected);
   }
 
@@ -323,9 +313,7 @@
     EXPECT_EQ(m_dense.rows(), 3);
     EXPECT_EQ(m_dense.cols(), 6);
     Matrix m_expected(3, 6);
-    m_expected << 1, 2, 0, 5, 6, 0,
-                  3, 4, 0, 7, 8, 0,
-                  0, 0, 9, 0, 0, 0;
+    m_expected << 1, 2, 0, 5, 6, 0, 3, 4, 0, 7, 8, 0, 0, 0, 9, 0, 0, 0;
     EXPECT_EQ(m_dense, m_expected);
   }
 }
diff --git a/internal/ceres/compressed_row_sparse_matrix.cc b/internal/ceres/compressed_row_sparse_matrix.cc
index da58b1a..9c78565 100644
--- a/internal/ceres/compressed_row_sparse_matrix.cc
+++ b/internal/ceres/compressed_row_sparse_matrix.cc
@@ -645,7 +645,9 @@
   CHECK_LE(options.block_density, 1.0);
 
   vector<int> row_blocks;
+  row_blocks.reserve(options.num_row_blocks);
   vector<int> col_blocks;
+  col_blocks.reserve(options.num_col_blocks);
 
   std::mt19937 prng;
   std::uniform_int_distribution<int> col_distribution(
diff --git a/internal/ceres/dense_cholesky.cc b/internal/ceres/dense_cholesky.cc
index a6220e4..244de74 100644
--- a/internal/ceres/dense_cholesky.cc
+++ b/internal/ceres/dense_cholesky.cc
@@ -33,6 +33,7 @@
 #include <algorithm>
 #include <memory>
 #include <string>
+#include <utility>
 #include <vector>
 
 #include "ceres/internal/config.h"
diff --git a/internal/ceres/dense_cholesky_test.cc b/internal/ceres/dense_cholesky_test.cc
index f8e6567..1c0df56 100644
--- a/internal/ceres/dense_cholesky_test.cc
+++ b/internal/ceres/dense_cholesky_test.cc
@@ -34,6 +34,7 @@
 #include <numeric>
 #include <sstream>
 #include <string>
+#include <utility>
 #include <vector>
 
 #include "Eigen/Dense"
diff --git a/internal/ceres/sparse_cholesky.cc b/internal/ceres/sparse_cholesky.cc
index 22df3c9..f68bfe2 100644
--- a/internal/ceres/sparse_cholesky.cc
+++ b/internal/ceres/sparse_cholesky.cc
@@ -31,6 +31,7 @@
 #include "ceres/sparse_cholesky.h"
 
 #include <memory>
+#include <utility>
 
 #include "ceres/accelerate_sparse.h"
 #include "ceres/eigensparse.h"