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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// <fstream>
// basic_streambuf<charT, traits>* setbuf(char_type* s, streamsize n) override;
#include <fstream>
#include <cstddef>
#include <cassert>
#include "test_macros.h"
template <class CharT>
static std::size_t file_size(const char* filename) {
FILE* f = std::fopen(filename, "rb");
std::fseek(f, 0, SEEK_END);
long result = std::ftell(f);
std::fclose(f);
return result;
}
// Helper class to expose some protected std::basic_filebuf<CharT> members.
template <class CharT>
struct filebuf : public std::basic_filebuf<CharT> {
CharT* base() { return this->pbase(); }
CharT* ptr() { return this->pptr(); }
};
template <class CharT>
static void buffered_request() {
filebuf<CharT> buffer;
CharT b[10] = {0};
assert(buffer.pubsetbuf(b, 10) == &buffer);
buffer.open("test.dat", std::ios_base::out);
buffer.sputc(CharT('a'));
assert(b[0] == 'a');
buffer.close();
assert(file_size<CharT>("test.dat") == 1);
}
template <class CharT>
static void unbuffered_request_before_open() {
filebuf<CharT> buffer;
assert(buffer.pubsetbuf(nullptr, 0) == &buffer);
assert(buffer.base() == nullptr);
assert(buffer.ptr() == nullptr);
buffer.open("test.dat", std::ios_base::out);
assert(buffer.base() == nullptr);
assert(buffer.ptr() == nullptr);
buffer.sputc(CharT('a'));
assert(buffer.base() == nullptr);
assert(buffer.ptr() == nullptr);
assert(file_size<CharT>("test.dat") == 1);
}
template <class CharT>
static void unbuffered_request_after_open() {
filebuf<CharT> buffer;
buffer.open("test.dat", std::ios_base::out);
assert(buffer.pubsetbuf(nullptr, 0) == &buffer);
assert(buffer.base() == nullptr);
assert(buffer.ptr() == nullptr);
buffer.sputc(CharT('a'));
assert(buffer.base() == nullptr);
assert(buffer.ptr() == nullptr);
assert(file_size<CharT>("test.dat") == 1);
}
template <class CharT>
static void unbuffered_request_after_open_ate() {
filebuf<CharT> buffer;
buffer.open("test.dat", std::ios_base::out | std::ios_base::ate);
assert(buffer.pubsetbuf(nullptr, 0) == &buffer);
buffer.sputc(CharT('a'));
assert(file_size<CharT>("test.dat") <= 1);
// on libc++ buffering is used by default.
LIBCPP_ASSERT(file_size<CharT>("test.dat") == 0);
buffer.close();
assert(file_size<CharT>("test.dat") == 1);
}
template <class CharT>
static void test() {
buffered_request<CharT>();
unbuffered_request_before_open<CharT>();
unbuffered_request_after_open<CharT>();
unbuffered_request_after_open_ate<CharT>();
}
int main(int, char**) {
test<char>();
#ifndef TEST_HAS_NO_WIDE_CHARACTERS
test<wchar_t>();
#endif
return 0;
}
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