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book: formatting style updates (#231)

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This commit is contained in:
ReEcho
2022-07-17 19:29:30 +08:00
committed by GitHub
parent 41b88c861e
commit e50e3c64f2
10 changed files with 104 additions and 74 deletions
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6
book/en-us/02-usability.md
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@@ -214,7 +214,8 @@ int main() {
}
// should output: 1, 4, 3, 4. can be simplified using `auto`
for (std::vector<int>::iterator element = vec.begin(); element != vec.end(); ++element)
for (std::vector<int>::iterator element = vec.begin(); element != vec.end();
++element)
std::cout << *element << std::endl;
}
```
@@ -301,7 +302,8 @@ int main() {
MagicFoo magicFoo = {1, 2, 3, 4, 5};
std::cout << "magicFoo: ";
for (std::vector<int>::iterator it = magicFoo.vec.begin(); it != magicFoo.vec.end(); ++it)
for (std::vector<int>::iterator it = magicFoo.vec.begin();
it != magicFoo.vec.end(); ++it)
std::cout << *it << std::endl;
}
```

12
book/en-us/03-runtime.md
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@@ -221,8 +221,8 @@ int foo(int a, int b, int c) {
;
}
int main() {
// bind parameter 1, 2 on function foo, and use std::placeholders::_1 as placeholder
// for the first parameter.
// bind parameter 1, 2 on function foo,
// and use std::placeholders::_1 as placeholder for the first parameter.
auto bindFoo = std::bind(foo, std::placeholders::_1, 1,2);
// when call bindFoo, we only need one param left
bindFoo(1);
@@ -355,7 +355,8 @@ int main()
std::string&& rv1 = std::move(lv1); // legal, std::move can convert lvalue to rvalue
std::cout << rv1 << std::endl; // string,
const std::string& lv2 = lv1 + lv1; // legal, const lvalue reference can extend temp variable's lifecycle
const std::string& lv2 = lv1 + lv1; // legal, const lvalue reference can
// extend temp variable's lifecycle
// lv2 += "Test"; // illegal, const ref can't be modified
std::cout << lv2 << std::endl; // string,string,
@@ -482,8 +483,9 @@ int main() {
// "str: Hello world."
std::cout << "str: " << str << std::endl;
// use push_back(const T&&), no copy
// the string will be moved to vector, and therefore std::move can reduce copy cost
// use push_back(const T&&),
// no copy the string will be moved to vector,
// and therefore std::move can reduce copy cost
v.push_back(std::move(str));
// str is empty now
std::cout << "str: " << str << std::endl;

14
book/en-us/05-pointers.md
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@@ -57,27 +57,27 @@ And see the reference count of an object by `use_count()`. E.g:
auto pointer = std::make_shared<int>(10);
auto pointer2 = pointer; // reference count+1
auto pointer3 = pointer; // reference count+1
int *p = pointer.get(); // no increase of reference count
int *p = pointer.get(); // no increase of reference count
std::cout << "pointer.use_count() = " << pointer.use_count() << std::endl; // 3
std::cout << "pointer.use_count() = " << pointer.use_count() << std::endl; // 3
std::cout << "pointer2.use_count() = " << pointer2.use_count() << std::endl; // 3
std::cout << "pointer3.use_count() = " << pointer3.use_count() << std::endl; // 3
pointer2.reset();
std::cout << "reset pointer2:" << std::endl;
std::cout << "pointer.use_count() = " << pointer.use_count() << std::endl; // 2
std::cout << "pointer.use_count() = " << pointer.use_count() << std::endl; // 2
std::cout << "pointer2.use_count() = "
<< pointer2.use_count() << std::endl; // 0, pointer2 has reset
<< pointer2.use_count() << std::endl; // pointer2 has reset, 0
std::cout << "pointer3.use_count() = " << pointer3.use_count() << std::endl; // 2
pointer3.reset();
std::cout << "reset pointer3:" << std::endl;
std::cout << "pointer.use_count() = " << pointer.use_count() << std::endl; // 1
std::cout << "pointer.use_count() = " << pointer.use_count() << std::endl; // 1
std::cout << "pointer2.use_count() = " << pointer2.use_count() << std::endl; // 0
std::cout << "pointer3.use_count() = "
<< pointer3.use_count() << std::endl; // 0, pointer3 has reset
<< pointer3.use_count() << std::endl; // pointer3 has reset, 0
```
## 5.3 `std::unique_ptr`
@@ -85,7 +85,7 @@ std::cout << "pointer3.use_count() = "
`std::unique_ptr` is an exclusive smart pointer that prohibits other smart pointers from sharing the same object, thus keeping the code safe:
```cpp
std::unique_ptr<int> pointer = std::make_unique<int>(10); // make_unique was introduced in C++14
std::unique_ptr<int> pointer = std::make_unique<int>(10); // make_unique, from C++14
std::unique_ptr<int> pointer2 = pointer; // illegal
```

46
book/en-us/06-regex.md
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@@ -84,8 +84,9 @@ We use a simple example to briefly introduce the use of this library. Consider t
int main() {
std::string fnames[] = {"foo.txt", "bar.txt", "test", "a0.txt", "AAA.txt"};
// In C++, `\` will be used as an escape character in the string. In order for `\.`
// to be passed as a regular expression, it is necessary to perform second escaping of `\`, thus we have `\\.`
// In C++, `\` will be used as an escape character in the string.
// In order for `\.` to be passed as a regular expression,
// it is necessary to perform second escaping of `\`, thus we have `\\.`
std::regex txt_regex("[a-z]+\\.txt");
for (const auto &fname: fnames)
std::cout << fname << ": " << std::regex_match(fname, txt_regex) << std::endl;
@@ -104,7 +105,8 @@ std::smatch base_match;
for(const auto &fname: fnames) {
if (std::regex_match(fname, base_match, base_regex)) {
// the first element of std::smatch matches the entire string
// the second element of std::smatch matches the first expression with brackets
// the second element of std::smatch matches the first expression
// with brackets
if (base_match.size() == 2) {
std::string base = base_match[1].str();
std::cout << "sub-match[0]: " << base_match[0].str() << std::endl;
@@ -187,32 +189,36 @@ Please implement the member functions `start()` and `parse_request`. Enable serv
template<typename SERVER_TYPE>
void start_server(SERVER_TYPE &server) {
// process GET request for /match/[digit+numbers], e.g.
// GET request is /match/abc123, will return abc123
server.resource["fill_your_reg_ex"]["GET"] = [](ostream& response, Request& request) {
// process GET request for /match/[digit+numbers],
// e.g. GET request is /match/abc123, will return abc123
server.resource["fill_your_reg_ex"]["GET"] =
[](ostream& response, Request& request)
{
string number=request.path_match[1];
response << "HTTP/1.1 200 OK\r\nContent-Length: " << number.length()
<< "\r\n\r\n" << number;
};
// peocess default GET request; anonymous function will be called if no other matches
// response files in folder web/
// peocess default GET request;
// anonymous function will be called
// if no other matches response files in folder web/
// default: index.html
server.default_resource["fill_your_reg_ex"]["GET"] =
[](ostream& response, Request& request) {
string filename = "www/";
[](ostream& response, Request& request)
{
string filename = "www/";
string path = request.path_match[1];
string path = request.path_match[1];
// forbidden use `..` access content outside folder web/
size_t last_pos = path.rfind(".");
size_t current_pos = 0;
size_t pos;
while((pos=path.find('.', current_pos)) != string::npos && pos != last_pos) {
current_pos = pos;
path.erase(pos, 1);
last_pos--;
}
// forbidden use `..` access content outside folder web/
size_t last_pos = path.rfind(".");
size_t current_pos = 0;
size_t pos;
while((pos=path.find('.', current_pos)) != string::npos && pos != last_pos) {
current_pos = pos;
path.erase(pos, 1);
last_pos--;
}
// (...)
};

18
book/en-us/07-thread.md
View File

@@ -145,7 +145,8 @@ int main() {
std::cout << "waiting...";
result.wait(); // block until future has arrived
// output result
std::cout << "done!" << std:: endl << "future result is " << result.get() << std::endl;
std::cout << "done!" << std:: endl << "future result is "
<< result.get() << std::endl;
return 0;
}
```
@@ -196,7 +197,8 @@ int main() {
// temporal unlock to allow producer produces more rather than
// let consumer hold the lock until its consumed.
lock.unlock();
std::this_thread::sleep_for(std::chrono::milliseconds(1000)); // consumer is slower
// consumer is slower
std::this_thread::sleep_for(std::chrono::milliseconds(1000));
lock.lock();
if (!produced_nums.empty()) {
std::cout << "consuming " << produced_nums.front() << std::endl;
@@ -272,7 +274,7 @@ This is a very strong set of synchronization conditions, in other words when it
This seems too harsh for a variable that requires only atomic operations (no intermediate state).
The research on synchronization conditions has a very long history, and we will not go into details here. Readers should understand that under the modern CPU architecture, atomic operations at the CPU instruction level are provided.
Therefore, in the C++11 multi-threaded shared variable reading and writing, the introduction of the `std::atomic` template, so that we instantiate an atomic type, will be a
Therefore, in the C++11 multi-threaded shared variable reading and writing, the introduction of the `std::atomic` template, so that we instantiate an atomic type, will be an
Atomic type read and write operations are minimized from a set of instructions to a single CPU instruction. E.g:
```cpp
@@ -417,8 +419,11 @@ Weakening the synchronization conditions between processes, usually we will cons
```
3 4 4 4 // The write operation of x was quickly observed
0 3 3 4 // There is a delay in the observed time of the x write operation
0 0 0 4 // The last read read the final value of x, but the previous changes were not observed.
0 0 0 0 // The write operation of x is not observed in the current time period, but the situation that x is 4 can be observed at some point in the future.
0 0 0 4 // The last read read the final value of x,
// but the previous changes were not observed.
0 0 0 0 // The write operation of x is not observed in the current time period,
// but the situation that x is 4 can be observed
// at some point in the future.
```
### Memory Orders
@@ -480,9 +485,8 @@ To achieve the ultimate performance and achieve consistency of various strength
});
std::thread acqrel([&]() {
int expected = 1; // must before compare_exchange_strong
while(!flag.compare_exchange_strong(expected, 2, std::memory_order_acq_rel)) {
while(!flag.compare_exchange_strong(expected, 2, std::memory_order_acq_rel))
expected = 1; // must after compare_exchange_strong
}
// flag has changed to 2
});
std::thread acquire([&]() {