String Utility

include: co/str.h.

#String operations

#str::cat

template <typename ...X>
inline fastring cat(X&& ... x);

  • Added in v2.0.3. Concatenate any number of elements to make a string.

  • 示例

str::cat("hello", ' ', 23);   // -> "hello 23"
str::cat("xx", 3.14, "true"); // -> "xx3.14true"

#str::replace

fastring replace(const char* s, size_t n, const char* sub, size_t m, const char* to, size_t l, size_t t=0);
fastring replace(const char* s, size_t n, const char* sub, const char* to, size_t t=0);

fastring replace(const char* s, const char* sub, const char* to, size_t t=0);
fastring replace(const fastring& s, const char* sub, const char* to, size_t t=0);
fastring replace(const std::string& s, const char* sub, const char* to, size_t t=0);

  • Replace substring sub in string s with to, n is the length of s, m is the length of sub, and l is the length of to; t is the maximum number of replacements, the default is 0 for unlimited.

  • The content of the original string s remains unchanged, and the new string after replacement is returned.

  • Example

str::replace("xooxoox", "oo", "ee");    // -> "xeexeex"
str::replace("xooxoox", "oo", "ee", 1); // -> "xeexoox"

#str::split

co::vector<fastring> split(const char* s, size_t n, char c, size_t t=0);
co::vector<fastring> split(const char* s, size_t n, const char* c, size_t m, size_t t=0);

co::vector<fastring> split(const char* s, char c, size_t t=0);
co::vector<fastring> split(const fastring& s, char c, size_t t=0);
co::vector<fastring> split(const std::string& s, char c, size_t t=0);

co::vector<fastring> split(const char* s, const char* c, size_t t=0);
co::vector<fastring> split(const fastring& s, const char* c, size_t t=0);
co::vector<fastring> split(const std::string& s, const char* c, size_t t=0);

  • Split string s into several substrings by delimiter c. n is the length of s, m is the length of c, t is the maximum number of splits, and 0 means unlimited.

  • The content of the original string s remains unchanged.

  • Example

str::split("x y z", '');   // -> ["x", "y", "z"]
str::split("|x|y|",'|');   // -> ["", "x", "y"]
str::split("xooy", "oo");  // -> ["x", "y"]
str::split("xooy",'o');    // -> ["x", "", "y"]
str::split("xooy",'o', 1); // -> ["x", "oy"]

#str::strip

template<typename ...X>
inline fastring strip(X&& ...x) {
    return trim(std::forward<X>(x)...);
}

#str::trim

fastring trim(const char* s, const char* c=" \t\r\n", char d='b');
fastring trim(const char* s, char c, char d='b');
fastring trim(const fastring& s, const char* c=" \t\r\n", char d='b');
fastring trim(const fastring& s, char c, char d='b');

  • Trim the string, removing character c or characters in string c from the left or right side of string s. The parameter d is the direction, ’l’ or ‘L’ means left, ‘r’ or ‘R’ means right, default is ‘b’ for both sides.

  • The content of the original string s remains unchanged.

  • Example

str::trim(" xx\r\n");         // -> "xx"
str::trim("abxxa", "ab");     // -> "xx"
str::trim("abxxa", "ab",'l'); // -> "xxa"
str::trim("abxxa", "ab",'r'); // -> "abxx"

#Conversion

#str::to_bool

bool to_bool(const char* s);
bool to_bool(const fastring& s);
bool to_bool(const std::string& s);

  • This function converts a string to bool type.

  • When s is equal to “0” or “false”, false is returned; when s is equal to “1” or “true”, true is returned.

  • If the conversion is successful, the error code is 0. Otherwise, the error code is set to EINVAL, and false is returned. Call co::error() to get the error code.

  • Example

bool b = str::to_bool("true");  // b = true
bool x = str::to_bool("false"); // x = false

#str::to_double

double to_double(const char* s);
double to_double(const fastring& s);
double to_double(const std::string& s);

  • This function converts a string to double type.

  • If the conversion is successful, the error code is 0. Otherwise, the error code is set to ERANGE or EINVAL, and 0 is returned. Call co::error() to get the error code.

  • Example

double x = str::to_double("3.14"); // x = 3.14

#str::to_int

int32 to_int32(const char* s);
int32 to_int32(const fastring& s);
int32 to_int32(const std::string& s);
int64 to_int64(const char* s);
int64 to_int64(const fastring& s);
int64 to_int64(const std::string& s);
uint32 to_uint32(const char* s);
uint32 to_uint32(const fastring& s);
uint32 to_uint32(const std::string& s);
uint64 to_uint64(const char* s);
uint64 to_uint64(const fastring& s);
uint64 to_uint64(const std::string& s);

  • These functions convert a string to integer types.

  • The parameter s can take one unit k, m, g, t, p at the end, which is not case sensitive.

  • If the conversion is successful, the error code is 0. Otherwise, the error code is set to ERANGE or EINVAL, and 0 is returned. Call co::error() to get the error code.

  • Example

int32 i32;
int64 i64;
uint32 u32;
uint64 u64;

i32 = str::to_int32("-23");  // -23
u32 = str::to_uint32("4k");  // 4096
i64 = str::to_int32("8M");   // 8 << 20
i64 = str::to_int64("8T");   // 8ULL << 40
u64 = str::to_int64("1P");   // 1ULL << 50

i32 = str::to_int32("8g");
LOG << (i32 == 0);
LOG << (errno == ERANGE);

i32 = str::to_int32("abx");
LOG << (i32 == 0);
LOG << (errno == EINVAL);

#str::from

template<typename T>
inline fastring from(T t);

  • This function converts built-in types to a string.

  • T can be any built-in type, such as bool, int, double, void*, etc.

  • Example

fastring s;
s = str::from(true); // -> "true"
s = str::from(23);   // -> "23"
s = str::from(3.14); // -> "3.14"

#str::dbg

template<typename T> fastring dbg(const co::vector<T>& v);
template<typename T> fastring dbg(const std::vector<T>& v);
template<typename T> fastring dbg(const co::list<T>& v);
template<typename T> fastring dbg(const std::list<T>& v);
template<typename T> fastring dbg(const co::deque<T>& v);
template<typename T> fastring dbg(const std::deque<T>& v);

template<typename T> fastring dbg(const co::set<T>& v);
template<typename T> fastring dbg(const std::set<T>& v);
template<typename T> fastring dbg(const co::hash_set<T>& v);
template<typename T> fastring dbg(const std::unordered_set<T>& v);

template<typename K, typename V>
fastring dbg(const co::map<K, V>& v);

template<typename K, typename V>
fastring dbg(const std::map<K, V>& v);

template<typename K, typename V>
fastring dbg(const co::hash_map<K, V>& v);

template<typename K, typename V>
fastring dbg(const std::unordered_map<K, V>& v);

template<typename K, typename V>
fastring dbg(const co::lru_map<K, V>& v);

  • This function converts a container to a debug string, which is generally for printing logs.

  • Example

std::vector<int> v {1, 2, 3 };
std::set<int> s {1, 2, 3 };
std::map<int, int> m {{1, 1}, {2, 2} };
str::dbg(v); // -> "[1,2,3]"
str::dbg(s); // -> "{1,2,3}"
str::dbg(m); // -> "{1:1,2:2}

std::vector<std::vector<int>> vv = {
    {1, 2, 3},
    {6, 7, 8},
};
str::dbg(vv); // -> "[[1,2,3],[6,7,8]]"
Since v3.0.1, str::dbg supports multiple nested containers.