diff --git a/fibonacci/cxx/06_general/test_fibonacci.cpp b/fibonacci/cxx/06_general/test_fibonacci.cpp
index 697ac45..6fa1a06 100644
--- a/fibonacci/cxx/06_general/test_fibonacci.cpp
+++ b/fibonacci/cxx/06_general/test_fibonacci.cpp
@@ -4,8 +4,7 @@
 #include "fibonacci.hpp"
 
 TEST_CASE("fibonacci", "test") {
-  const std::vector<std::tuple<int, int>> cases{
-      {0, 0}, {1, 1}, {2, 1}, {3, 2}, {10, 55}};
+  const std::vector<std::tuple<int, int>> cases{{0, 0}, {1, 1}, {2, 1}, {3, 2}, {10, 55}};
   for (auto&& nv : cases) {
     const auto n = std::get<0>(nv);
     const auto v = std::get<1>(nv);
diff --git a/fibonacci/cxx/07_negative/test_fibonacci.cpp b/fibonacci/cxx/07_negative/test_fibonacci.cpp
index a28c05e..939739a 100644
--- a/fibonacci/cxx/07_negative/test_fibonacci.cpp
+++ b/fibonacci/cxx/07_negative/test_fibonacci.cpp
@@ -4,8 +4,7 @@
 #include "fibonacci.hpp"
 
 TEST_CASE("fibonacci", "test") {
-  const std::vector<std::tuple<int, int>> cases{
-      {-2, -1}, {-1, 1}, {0, 0}, {1, 1}, {2, 1}, {3, 2}, {10, 55}};
+  const std::vector<std::tuple<int, int>> cases{{-2, -1}, {-1, 1}, {0, 0}, {1, 1}, {2, 1}, {3, 2}, {10, 55}};
   for (auto &&nv : cases) {
     const auto n = std::get<0>(nv);
     const auto v = std::get<1>(nv);
diff --git a/fibonacci/cxx/08_linear/fibonacci.hpp b/fibonacci/cxx/08_linear/fibonacci.hpp
index f6e2895..5206837 100644
--- a/fibonacci/cxx/08_linear/fibonacci.hpp
+++ b/fibonacci/cxx/08_linear/fibonacci.hpp
@@ -6,15 +6,21 @@ inline int fibonacci(int n) {
   int v0 = 0;
   int v1 = 1;
   if (n < 0) {
-    for (int i = -1; i >= n; --i)
-      std::tie(v0, v1) = std::make_tuple(v1 - v0, v0);
+    for (int i = -1; i >= n; --i) {
+      auto v0_old = v0;
+      v0 = v1 - v0_old;
+      v1 = v0_old;
+    }
     return v0;
   }
   if (n == 0)
     return v0;
   if (n == 1)
     return v1;
-  for (int i = 2; i <= n; ++i)
-    std::tie(v1, v0) = std::make_tuple(v0 + v1, v1);
+  for (int i = 2; i <= n; ++i) {
+    auto v1_old = v1;
+    v1 = v0 + v1_old;
+    v0 = v1_old;
+  }
   return v1;
 }
diff --git a/fibonacci/cxx/08_linear/test_fibonacci.cpp b/fibonacci/cxx/08_linear/test_fibonacci.cpp
index fe989be..fdbfc8d 100644
--- a/fibonacci/cxx/08_linear/test_fibonacci.cpp
+++ b/fibonacci/cxx/08_linear/test_fibonacci.cpp
@@ -4,9 +4,7 @@
 #include "fibonacci.hpp"
 
 TEST_CASE("fibonacci", "test") {
-  const std::vector<std::tuple<int, int>> cases{
-      {-2, -1}, {-1, 1}, {0, 0},   {1, 1},
-      {2, 1},   {3, 2},  {10, 55}, {40, 102334155}};
+  const std::vector<std::tuple<int, int>> cases{{-2, -1}, {-1, 1}, {0, 0}, {1, 1}, {2, 1}, {3, 2}, {10, 55}, {40, 102334155}};
   for (auto &&nv : cases) {
     const auto n = std::get<0>(nv);
     const auto v = std::get<1>(nv);
diff --git a/fibonacci/cxx/09_multiprec/fibonacci.hpp b/fibonacci/cxx/09_multiprec/fibonacci.hpp
index 43c55dd..1c21d40 100644
--- a/fibonacci/cxx/09_multiprec/fibonacci.hpp
+++ b/fibonacci/cxx/09_multiprec/fibonacci.hpp
@@ -1,6 +1,5 @@
 #pragma once
 
-#include <tuple>
 #include <boost/multiprecision/cpp_int.hpp>
 
 namespace mp = boost::multiprecision;
@@ -9,15 +8,21 @@ inline mp::cpp_int fibonacci(int n) {
   mp::cpp_int v0 = 0;
   mp::cpp_int v1 = 1;
   if (n < 0) {
-    for (int i = -1; i >= n; --i)
-      std::tie(v0, v1) = std::make_tuple(v1 - v0, v0);
+    for (int i = -1; i >= n; --i) {
+      auto v0_old = v0;
+      v0 = v1 - v0_old;
+      v1 = v0_old;
+    }
     return v0;
   }
   if (n == 0)
     return v0;
   if (n == 1)
     return v1;
-  for (int i = 2; i <= n; ++i)
-    std::tie(v1, v0) = std::make_tuple(v0 + v1, v1);
+  for (int i = 2; i <= n; ++i) {
+    auto v1_old = v1;
+    v1 = v0 + v1_old;
+    v0 = v1_old;
+  }
   return v1;
 }
diff --git a/fibonacci/cxx/09_multiprec/test_fibonacci.cpp b/fibonacci/cxx/09_multiprec/test_fibonacci.cpp
index b27b142..541c168 100644
--- a/fibonacci/cxx/09_multiprec/test_fibonacci.cpp
+++ b/fibonacci/cxx/09_multiprec/test_fibonacci.cpp
@@ -4,18 +4,7 @@
 #include "fibonacci.hpp"
 
 TEST_CASE("fibonacci", "test") {
-  const std::vector<std::tuple<int, mp::cpp_int>> cases{
-      {-2, -1},
-      {-1, 1},
-      {0, 0},
-      {1, 1},
-      {2, 1},
-      {3, 2},
-      {10, 55},
-      {40, 102334155},
-      {100, mp::cpp_int("354224848179261915075")},
-      {250,
-       mp::cpp_int("7896325826131730509282738943634332893686268675876375")}};
+  const std::vector<std::tuple<int, mp::cpp_int>> cases{{-2, -1}, {-1, 1}, {0, 0}, {1, 1}, {2, 1}, {3, 2}, {10, 55}, {40, 102334155}, {100, mp::cpp_int("354224848179261915075")}};
   for (auto &&nv : cases) {
     const auto n = std::get<0>(nv);
     const auto v = std::get<1>(nv);
diff --git a/fibonacci/cxx/10_lucas/recursion.hpp b/fibonacci/cxx/10_lucas/recursion.hpp
index 23dea0a..af91ed9 100644
--- a/fibonacci/cxx/10_lucas/recursion.hpp
+++ b/fibonacci/cxx/10_lucas/recursion.hpp
@@ -1,21 +1,26 @@
 #pragma once
 
-#include <tuple>
 #include <boost/multiprecision/cpp_int.hpp>
 
 namespace mp = boost::multiprecision;
 
 inline mp::cpp_int recursion(mp::cpp_int v0, mp::cpp_int v1, int n) {
   if (n < 0) {
-    for (int i = -1; i >= n; --i)
-      std::tie(v0, v1) = std::make_tuple(v1 - v0, v0);
+    for (int i = -1; i >= n; --i) {
+      auto v0_old = v0;
+      v0 = v1 - v0_old;
+      v1 = v0_old;
+    }
     return v0;
   }
   if (n == 0)
     return v0;
   if (n == 1)
     return v1;
-  for (int i = 2; i <= n; ++i)
-    std::tie(v1, v0) = std::make_tuple(v0 + v1, v1);
+  for (int i = 2; i <= n; ++i) {
+    auto v1_old = v1;
+    v1 = v0 + v1_old;
+    v0 = v1_old;
+  }
   return v1;
 }
diff --git a/fibonacci/cxx/10_lucas/test_fibonacci.cpp b/fibonacci/cxx/10_lucas/test_fibonacci.cpp
index b27b142..541c168 100644
--- a/fibonacci/cxx/10_lucas/test_fibonacci.cpp
+++ b/fibonacci/cxx/10_lucas/test_fibonacci.cpp
@@ -4,18 +4,7 @@
 #include "fibonacci.hpp"
 
 TEST_CASE("fibonacci", "test") {
-  const std::vector<std::tuple<int, mp::cpp_int>> cases{
-      {-2, -1},
-      {-1, 1},
-      {0, 0},
-      {1, 1},
-      {2, 1},
-      {3, 2},
-      {10, 55},
-      {40, 102334155},
-      {100, mp::cpp_int("354224848179261915075")},
-      {250,
-       mp::cpp_int("7896325826131730509282738943634332893686268675876375")}};
+  const std::vector<std::tuple<int, mp::cpp_int>> cases{{-2, -1}, {-1, 1}, {0, 0}, {1, 1}, {2, 1}, {3, 2}, {10, 55}, {40, 102334155}, {100, mp::cpp_int("354224848179261915075")}};
   for (auto &&nv : cases) {
     const auto n = std::get<0>(nv);
     const auto v = std::get<1>(nv);
diff --git a/fibonacci/cxx/10_lucas/test_lucas.cpp b/fibonacci/cxx/10_lucas/test_lucas.cpp
index b27c0b2..1f4f71e 100644
--- a/fibonacci/cxx/10_lucas/test_lucas.cpp
+++ b/fibonacci/cxx/10_lucas/test_lucas.cpp
@@ -4,19 +4,10 @@
 #include "lucas.hpp"
 
 TEST_CASE("lucas", "test") {
-  const std::vector<std::tuple<int, mp::cpp_int>> cases{
-      {-2, 3},
-      {-1, -1},
-      {0, 2},
-      {1, 1},
-      {2, 3},
-      {3, 4},
-      {10, 123},
-      {40, 228826127},
-      {100, mp::cpp_int("792070839848372253127")},
-      {250,
-       mp::cpp_int("17656721319717734662791328845675730903632844218828123")}};
-  for (auto &&[n, v] : cases) {
+  const std::vector<std::tuple<int, mp::cpp_int>> cases{{-2, 3}, {-1, -1}, {0, 2}, {1, 1}, {2, 3}, {3, 4}, {10, 123}, {40, 228826127}, {100, mp::cpp_int("792070839848372253127")}};
+  for (auto &&nv : cases) {
+    const auto n = std::get<0>(nv);
+    const auto v = std::get<1>(nv);
     REQUIRE(lucas(n) == v);
     if (n > 0)
       REQUIRE(lucas(n) > 0);
diff --git a/tdd-tutorial.key b/tdd-tutorial.key
index 8dfcc75..b3b466f 100644
Binary files a/tdd-tutorial.key and b/tdd-tutorial.key differ