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Added format_arg() for integral and floating point types and char arrays

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This commit is contained in:
Andreas Tsouchlos 2021-11-21 18:52:07 +01:00
parent 6afb5bea87
commit 53091a30cd
2 changed files with 53 additions and 22 deletions
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71
inc/format.h
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@ -11,7 +11,7 @@ namespace detail {
template <ConstString s>
constexpr int get_output_len() {
constexpr auto parse_result = parse_string<s>();
static_assert(parse_result.is_valid, "Syntax error in log string");
static_assert(parse_result.is_valid, "Syntax error in format string");
unsigned result = 0;
@ -25,42 +25,75 @@ constexpr int get_output_len() {
return result;
}
template <typename T, fmt_node_t fmt_node>
constexpr bool is_valid_type() {
// TODO
return true;
}
template <fmt_node_t fmt_node, typename T>
constexpr std::array<char, fmt_node.length> format_arg(T arg) {
static_assert(is_valid_type<T, fmt_node>(), "Invalid argument type");
template <fmt_node_t fmt_node, std::integral arg_t>
constexpr std::array<char, fmt_node.length> format_arg(arg_t arg) {
std::array<char, fmt_node.length> result;
// TODO: See if this is possible with charconv
for (unsigned i = 1; i <= result.size(); ++i) {
result[result.size() - i] = arg % 10 + 48;
arg = arg / 10;
}
return result;
}
template <fmt_node_t fmt_node, std::floating_point arg_t>
constexpr std::array<char, fmt_node.length> format_arg(arg_t) {
std::array<char, fmt_node.length> result;
// TODO: See if this is possible with charconv
for (auto& c : result)
c = 'f';
return result;
}
template <fmt_node_t fmt_node>
constexpr std::array<char, fmt_node.length> format_arg(const char* arg) {
std::array<char, fmt_node.length> result;
template<auto t_ast, unsigned t_ast_i=0, unsigned t_result_i=0, typename char_array_t, typename first_arg_t, typename... other_args_t>
constexpr char_array_t format_args(char_array_t result, first_arg_t first_arg, other_args_t... other_args) {
if constexpr(t_ast_i >= t_ast.size()) {
for (auto& c : result) {
if (*arg != '\0')
c = *(arg++);
else
c = '-';
}
return result;
}
template <auto t_ast, unsigned t_ast_i = 0, unsigned t_result_i = 0,
typename char_array_t>
constexpr char_array_t format_args(char_array_t result) {
return result;
}
template <auto t_ast, unsigned t_ast_i = 0, unsigned t_result_i = 0,
typename char_array_t, typename first_arg_t, typename... other_args_t>
constexpr char_array_t format_args(char_array_t result, first_arg_t first_arg,
other_args_t... other_args) {
if constexpr (t_ast_i >= t_ast.size()) {
return result;
} else {
constexpr auto ast_node = t_ast[t_ast_i];
if (ast_node.is_char()) {
result[t_result_i] = ast_node.get_char();
return format_args<t_ast, t_ast_i+1, t_result_i+1>(result, first_arg, other_args...);
return format_args<t_ast, t_ast_i + 1, t_result_i + 1>(
result, first_arg, other_args...);
} else {
constexpr auto fmt_node = ast_node.get_node();
const auto formatted_arg = format_arg<fmt_node>(first_arg);
constexpr auto fmt_node = ast_node.get_node();
const auto formatted_arg = format_arg<fmt_node>(first_arg);
std::copy(formatted_arg.begin(), formatted_arg.end(), result.begin()+t_result_i);
std::copy(formatted_arg.begin(), formatted_arg.end(),
result.begin() + t_result_i);
return format_args<t_ast, t_ast_i+1, t_result_i+fmt_node.length>(result, first_arg, other_args...);
return format_args<t_ast, t_ast_i + 1,
t_result_i + fmt_node.length>(result, other_args...);
}
}
}
@ -72,7 +105,7 @@ constexpr char_array_t format_args(char_array_t result, first_arg_t first_arg, o
template <detail::ConstString s, typename... args_t>
std::array<char, detail::get_output_len<s>()> format(args_t... args) {
constexpr auto parse_result = detail::parse_string<s>();
static_assert(parse_result.is_valid);
static_assert(parse_result.is_valid, "Syntax error in format string");
std::array<char, detail::get_output_len<s>()> result;

4
src/main.cpp
View File

@ -12,9 +12,7 @@ public:
int main() {
constexpr detail::ConstString s{"Test: {:3.8f} {:02.5} {:05.2}"};
const auto formatted = format<s>(3.4, "abc", 8.98754);
const auto formatted = format<"Test: {:3.8f} {:5.5} {:05.2}">(3.4, "abc", 1234);
for (const auto& c : formatted)
std::cout << c;