c++ - 无法创建具有值和绑定(bind)的 std::ranges::iota_view

Question

我试图创建一个 std::ranges::iota_view有一个值和一个界限:

#include <ranges>
#include <vector>

int main() {
  std::vector v{1,2,3};
  auto indices = std::ranges::views::iota(0, v.size());
}

link to program on godbolt

但是 clang 11.0.0 编译失败，报错信息:

no viable constructor or deduction guide for deduction of template arguments of 'iota_view'

我做错了什么？

Answer 1

来自 https://en.cppreference.com/w/cpp/ranges/iota_view

Note that the [deduction] guide protects itself against signed/unsigned mismatch bugs, like views::iota(0, v.size()), where 0 is a (signed) int and v.size() is an (unsigned) std::size_t.

这会起作用:

auto indices = std::ranges::views::iota(0u, v.size());
                                         ^ unsigned zero literal

不幸的是，Clang 似乎还有另一个错误，但它 works in gcc ;或者你可以 use range-v3 .