to¶
name¶
to - do the opposite of fast_io::concate()
. Convert string to integer
/ floating point / etc.
synopsis¶
#include<fast_io.h>
constexpr T to<T>(args ...)
description¶
The function to()
take one or more strings and returns the conversion
result truncated from the first unexpected character (depending on the
specified template parameter T).
return_value¶
The function returns the conversion result with specified type T. Return
value type can be specified by specifying the first template parameter T
while calling to()
.
example¶
convert string to integer:
#include<fast_io.h>
int main() {
std::string answer{"42"};
auto result{fast_io::to<uint32_t>(answer)};
// tell to() what to do by specifying T
println("the answer is ",result);
}
convert multiple strings to one integer:
#include<fast_io.h>
int main() {
std::string part1{"123"};
std::string part2{"456"};
std::string part3{"789"};
auto result = fast_io::to<int32_t>(part1,part2,part3);
println("the result is: ",result);
}
anything after the first unexpected character will be ignored, even if they are expected ones:
#include<fast_io.h>
int main() {
std::string with_point{"123456789"};
std::string with_char{"123456A789"};
std::string with_star{"123456*789"};
// if the first character is illegal, 0 will be returned.
std::string with_etc{"~!@#$%^&*()_+{}|:\"<>?`-=[]\\;',./'`"};
println("with point: ",with_point," -> ",fast_io::to<int32_t>(with_point));
println("with char: ",with_char," -> ",fast_io::to<int32_t>(with_char));
println("with star: ",with_star," -> ",fast_io::to<int32_t>(with_star));
println("with other: ",with_etc," -> ",fast_io::to<int32_t>(with_etc));
}