std::basic_string_view::remove_prefix

 

C++

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Language support library

Concepts library (C++20)

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Utilities library

Strings library

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Regular expressions library (C++11)

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Technical Specifications

 

Strings library

Null-terminated strings

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Classes

basic_string

basic_string_view (C++17)

char_traits

 

std::basic_string_view

Member functions basic_string_view::basic_string_view basic_string_view::operator= Iterators basic_string_view::beginbasic_string_view::cbegin basic_string_view::endbasic_string_view::cend basic_string_view::rbeginbasic_string_view::crbegin basic_string_view::rendbasic_string_view::crend Element access basic_string_view::at basic_string_view::operator[] basic_string_view::front basic_string_view::back basic_string_view::data Capacity basic_string_view::sizebasic_string_view::length basic_string_view::max_size basic_string_view::empty Modifers basic_string_view::remove_prefix basic_string_view::remove_suffix basic_string_view::swap

Operations basic_string_view::copy basic_string_view::substr basic_string_view::compare basic_string_view::starts_with (C++20) basic_string_view::ends_with (C++20) basic_string_view::find basic_string_view::rfind basic_string_view::find_first_of basic_string_view::find_last_of basic_string_view::find_first_not_of basic_string_view::find_last_not_of Constants basic_string_view::npos Non-member functions operator==operator!=operator<operator>operator<=operator>= operator<< operator""sv Helper classes hash<std::string_view>hash<std::wstring_view>hash<std::u16string_view>hash<std::u32string_view>

 

constexpr void remove_prefix(size_type n);		(since C++17)

Moves the start of the view forward by n characters.

The behavior is undefined if n > size().

Parameters

n

-

number of characters to remove from the start of the view

Return value

(none)

Complexity

Constant.

Example

Run this code

#include <iostream>
#include <algorithm>
#include <string_view>
int main()
{
    std::string str = "   trim me";
    std::string_view v = str;
    v.remove_prefix(std::min(v.find_first_not_of(" "), v.size()));
    std::cout << "String: '" << str << "'\n"
              << "View  : '" << v << "'\n";
}

Output:

String: '   trim me'
View  : 'trim me'

See also

remove_suffix

shrinks the view by moving its end backward (public member function)