#include <gtest/gtest.h>
#include <xgboost/string_view.h>
#include <algorithm>
#include <sstream>
#include <string>
namespace xgboost {
TEST(StringView, Basic) {
StringView str{"This is a string."};
std::stringstream ss;
ss << str;
std::string res = ss.str();
ASSERT_EQ(str.size(), res.size());
ASSERT_TRUE(std::equal(res.cbegin(), res.cend(), str.cbegin()));
auto substr = str.substr(5, 2);
ASSERT_EQ(substr.size(), 2);
ASSERT_EQ(StringView{"is"}.size(), 2);
ASSERT_TRUE(substr == "is");
ASSERT_FALSE(substr != "is");
ASSERT_FALSE(substr == "foobar");
ASSERT_FALSE(substr == "i");
ASSERT_TRUE(std::equal(substr.crbegin(), substr.crend(), StringView{"si"}.cbegin()));
{
StringView empty{nullptr};
ASSERT_TRUE(empty.empty());
}
{
StringView empty{""};
ASSERT_TRUE(empty.empty());
StringView empty2{nullptr};
ASSERT_EQ(empty, empty2);
}
}
}