May 27, 2024 · May 25, 2024 · May 25, 2024 · May 25, 2024 · May 26, 2024
diff --git a/01-string-and-character-literals.md b/01-string-and-character-literals.md
 Our wanderings to guide.
 ```

 * Now use a (non-raw) string literal for each line and a single call to `print()` with suitable escape characters.What happens if you remove all ofthestream insertion operators *except* for the first? (Explanation: *concatenation* of adjacent string literals is automatically performed by the pre-processor.)
 * Now use a (non-raw) string literal for each line and a single call to `print()` with suitable escape characters.You concatenatethestring literals without any operator: *concatenation* of adjacent string literals is automatically performed by the pre-processor.

 * Modify `01-title.cpp` to output the title of your favorite book or film centered on the console window (assume an 80 character fixed width, and change the size of the console window if different).

 | char32_t |   32  |  UTF-32  |     U"abcd"    |        U'a'       |     UR"(abcd)"     |  u32string  |      n/a      |   no    |
 |  wchar_t | 16/32 |   n/a +  |     L"abcd"    |        L'a'       |     LR"(abcd)"     |   wstring   |  wcout/wcerr  |   no    |

 &#42; An explicit cast to type `char` in `operator<<` may be required when using `cout`/`cerr`, for example: `cout <<static_cast<char>(u8"Hello \u20AC!\n");`.
 &#42; An explicit cast to type `char` in `operator<<` may be required when using `cout`/`cerr`, for example: `cout <<reinterpret_cast<constchar*>(u8"Hello \u20AC!\n");`.

 &#43; The `wchar_t` encoding and streams under Windows are 16-bit and support UTF-16.

diff --git a/02-variables-scopes-and-namespaces.md b/02-variables-scopes-and-namespaces.md
 #include <cmath>
 using namespace std;

 // Note: currently, not all compilers mark `acos` as a
 // constexpr function in cmath. The following line might
 // not compile with `clang++` for example.
 constexpr double PI1 = acos(-1.0);
 constexpr double PI2 = 22.0 / 7.0;

 }
 ```

 (Hint: this program is the first to require an additional header to `<print>`; you may need to add `-lm` to the compile command under Linux/MacOS in order to link in the math library containing the `acos()` function.)
 (Hint: this program is the first to require an additional header to `<print>`; you may need to add `-lm` to the compile command under Linux in order to link in the math library containing the `acos()` function.)

 **Experiment**

diff --git a/04-functions.md b/04-functions.md
 #include <stdexcept>
 using namespace std;

 void throw_if_zero(int i) {
 void throw_if_zero(int i)noexcept{
    if (!i) {
        throw runtime_error("found a zero");
    }
Original file line number	Diff line number	Diff line change
Expand Up		@@ -133,7 +133,7 @@ While little hands make vain pretence
		Our wanderings to guide.
		```

		* Now use a (non-raw) string literal for each line and a single call to `print()` with suitable escape characters.What happens if you remove all ofthestream insertion operators except for the first? (Explanation: concatenation of adjacent string literals is automatically performed by the pre-processor.)
		* Now use a (non-raw) string literal for each line and a single call to `print()` with suitable escape characters.You concatenatethestring literals without any operator: concatenation of adjacent string literals is automatically performed by the pre-processor.

		* Modify `01-title.cpp` to output the title of your favorite book or film centered on the console window (assume an 80 character fixed width, and change the size of the console window if different).

Expand All		@@ -156,7 +156,7 @@ The following table lists C++ types, sizes, target encodings, literals and objec
		\| char32_t \| 32 \| UTF-32 \| U"abcd" \| U'a' \| UR"(abcd)" \| u32string \| n/a \| no \|
		\| wchar_t \| 16/32 \| n/a + \| L"abcd" \| L'a' \| LR"(abcd)" \| wstring \| wcout/wcerr \| no \|

		* An explicit cast to type `char` in `operator<<` may be required when using `cout`/`cerr`, for example: `cout <<static_cast<char>(u8"Hello \u20AC!\n");`.
		* An explicit cast to type `char` in `operator<<` may be required when using `cout`/`cerr`, for example: `cout <<reinterpret_cast<constchar*>(u8"Hello \u20AC!\n");`.

		+ The `wchar_t` encoding and streams under Windows are 16-bit and support UTF-16.

Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -468,6 +468,9 @@ In fact, `constexpr` expressions can be complex with recent compilers, as long a
		#include <cmath>
		using namespace std;

		// Note: currently, not all compilers mark `acos` as a
		// constexpr function in cmath. The following line might
		// not compile with `clang++` for example.
		constexpr double PI1 = acos(-1.0);
		constexpr double PI2 = 22.0 / 7.0;

Expand All		@@ -480,7 +483,7 @@ int main() {
		}
		```

		(Hint: this program is the first to require an additional header to `<print>`; you may need to add `-lm` to the compile command under Linux/MacOS in order to link in the math library containing the `acos()` function.)
		(Hint: this program is the first to require an additional header to `<print>`; you may need to add `-lm` to the compile command under Linux in order to link in the math library containing the `acos()` function.)

		Experiment

Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -538,7 +538,7 @@ The keyword `noexcept` is used to declare that a function is guaranteed to not t
		#include <stdexcept>
		using namespace std;

		void throw_if_zero(int i) {
		void throw_if_zero(int i)noexcept{
		if (!i) {
		throw runtime_error("found a zero");
		}
Expand Down