Overview
The RowStream class provides a stream-based interface for building table rows dynamically. It allows you to use stream insertion operators (<<) to construct rows, similar to how you would use std::ostringstream.
Constructor
Creates a new empty RowStream object.
Type Conversion
operator Table::Row_t
operator const Table::Row_t&() const
Table::Row_t, allowing it to be used directly with Table::add_row().
Stream Insertion
operator<<
template<typename T>
RowStream& operator<<(const T& obj)
std::ostringstream.
The value to insert into the row. Can be any type that supports stream insertion.
RowStream& operator<<(const Table::Row_t::value_type& cell)
cell
const Table::Row_t::value_type&
The cell value to insert.
copyfmt
RowStream& copyfmt(const RowStream& other)
RowStream& copyfmt(const std::ios& other)
fill
std::ostringstream::char_type fill() const
std::ostringstream::char_type fill(std::ostringstream::char_type ch)
exceptions
std::ios_base::iostate exceptions() const
void exceptions(std::ios_base::iostate except)
imbue / getloc
std::locale imbue(const std::locale& loc)
std::locale getloc() const
narrow / widen
char narrow(std::ostringstream::char_type c, char dfault) const
std::ostringstream::char_type widen(char c) const
flags
std::ios::fmtflags flags() const
std::ios::fmtflags flags(std::ios::fmtflags flags)
setf / unsetf
std::ios::fmtflags setf(std::ios::fmtflags flags)
std::ios::fmtflags setf(std::ios::fmtflags flags, std::ios::fmtflags mask)
void unsetf(std::ios::fmtflags flags)
precision
std::streamsize precision() const
std::streamsize precision(std::streamsize new_precision)
width
std::streamsize width() const
std::streamsize width(std::streamsize new_width)
Usage Examples
Basic Usage
#include <tabulate/table.hpp>
using namespace tabulate;
int main() {
Table table;
// Create a row using RowStream
RowStream row1;
row1 << "Name" << "Age" << "City";
table.add_row(row1);
// Or use directly in add_row
RowStream row2;
row2 << "Alice" << 25 << "New York";
table.add_row(row2);
std::cout << table << std::endl;
}
Table financial;
RowStream header;
header << "Account" << "Balance" << "Interest Rate";
financial.add_row(header);
// Format numbers with precision
RowStream data;
data << "Savings";
data << std::fixed << std::setprecision(2) << 12345.678;
data << std::fixed << std::setprecision(2) << 2.5 << "%";
financial.add_row(data);
std::cout << financial << std::endl;
Mixed Types
Table metrics;
RowStream row;
row << "Server Load"; // string
row << 87; // integer
row << 92.5; // double
row << true; // boolean (displays as 1)
row << "Active"; // string
metrics.add_row(row);
Dynamic Row Building
Table report;
// Build row dynamically based on conditions
RowStream row;
row << "Product A";
int stock = 150;
if (stock > 100) {
row << "In Stock" << stock;
} else if (stock > 0) {
row << "Low Stock" << stock;
} else {
row << "Out of Stock" << 0;
}
report.add_row(row);
Nested Tables
Table outer;
// Create inner table
Table inner;
inner.add_row({"A", "B"});
inner.add_row({"1", "2"});
// Use RowStream to add nested table
RowStream row;
row << "Nested Table:" << inner;
outer.add_row(row);
std::cout << outer << std::endl;
Table scientific_data;
RowStream header;
header << "Measurement" << "Value" << "Error";
scientific_data.add_row(header);
RowStream data;
data << "Speed of Light";
// Use scientific notation
data << std::scientific << std::setprecision(4) << 299792458.0;
data << std::scientific << std::setprecision(2) << 0.0001;
scientific_data.add_row(data);
std::cout << scientific_data << std::endl;
Building Multiple Rows in a Loop
Table times_table;
// Header
RowStream header;
header << "x";
for (int i = 1; i <= 5; ++i) {
header << i;
}
times_table.add_row(header);
// Data rows
for (int i = 1; i <= 5; ++i) {
RowStream row;
row << i; // First column
for (int j = 1; j <= 5; ++j) {
row << (i * j);
}
times_table.add_row(row);
}
std::cout << times_table << std::endl;
Complete Example
#include <tabulate/table.hpp>
#include <iomanip>
using namespace tabulate;
int main() {
Table sales_report;
// Add header using RowStream
RowStream header;
header << "Product" << "Units Sold" << "Price" << "Revenue";
sales_report.add_row(header);
sales_report[0].format()
.font_style({FontStyle::bold})
.font_color(Color::yellow)
.font_align(FontAlign::center);
// Add data rows with formatted numbers
struct Product {
std::string name;
int units;
double price;
};
std::vector<Product> products = {
{"Laptop", 42, 999.99},
{"Mouse", 156, 29.99},
{"Keyboard", 89, 79.99},
{"Monitor", 31, 299.99}
};
for (const auto& product : products) {
RowStream row;
row << product.name;
row << product.units;
row << "$" << std::fixed << std::setprecision(2) << product.price;
row << "$" << std::fixed << std::setprecision(2)
<< (product.units * product.price);
sales_report.add_row(row);
}
// Format table
sales_report.column(0).format().width(15);
sales_report.column(1).format().width(12).font_align(FontAlign::center);
sales_report.column(2).format().width(10).font_align(FontAlign::right);
sales_report.column(3).format().width(12).font_align(FontAlign::right)
.font_color(Color::green);
sales_report.format().border_color(Color::cyan);
std::cout << sales_report << std::endl;
return 0;
}
Notes
RowStream automatically converts non-string types to strings using std::ostringstream. This means you can use standard stream manipulators like std::fixed, std::setprecision, std::hex, etc.
Each value inserted into a RowStream becomes a separate cell in the table. If you want multiple values in a single cell, convert them to a string first.
